Sometimes people have to play against that 6-year-old next door.  She's
got gobs of cards but a negative amount of strategy.  But since you feel
kinda guilty, being over a decade older than her, you just have to lose a
game every now and then.  On Purpose.  Now this sounds kind of lame, I admit,
but this is taking "learning from defeat" to the next level.  Being defeated
on purpose so you can learn what NOT to do!  Also you can get brownie points
with Pee Wee's mom... maybe extra money for babysitting!!
        Here's some advice!
    Loser Deck Building Rule #1:
        You have to make it look good.  Don't just stick out Abra's and
Magikarp's.  Toss in a few evolutions!  Since Pee Wee's morale is down
because of the booster chair, destroying one of your Stage 1 pokemon is an
ego booster!  It's even better when you deliberately set up a Charizard when
you know Pee Wee is going with a water deck.  (and you can "accidentially"
not get any energy for it, and if Pee Wee knocks out your mighty Charizard
with their Magikarp they'll have something to brag about to their friends at
school)
    Loser Deck Building Rule #2: 
        About those trainers.  Don't put in any of the "meanie" ones, like
energy removal or gust of wind.  Don't even bother with too many potions or
Bills.  Heck, you can just let the entire "trainer" card section gather dust
while you're having your big Pee Wee tournament!  Remember, nothing too fancy
(even *I* was confused about Pokemon Breeder for a while there!)
            Tip:  Toss in a LOT of energy.  Energy you don't need.  Energy
that doesn't correspond to your type.  Since you're losing anyhow, you might
as well have a pretty hand to look at.  ("Oooh, a rainbow!") 

        Okay, maybe you don't want to MAKE a loser deck.  But you can make a
winning deck into a loser deck by playing in a wretched manner.  Don't
evolve, or evolve too quickly.  Use Switch when you don't need it, ignore
most of your trainers, though maybe you should use Professor Oak so Gyarados'
adorable shiny little eyes don't look at you reproachfully from the back of
your hand for the whole game!  Put down mis-matched energy!  Use those stupid
attacks!  Yes, you know the ones i'm talking about!  The attacks that they
added to otherwise nice cards which no sane person would use!  Well, okay,
I've seen Pee Wees use them, but they're six, come on!

NOTICE: Pee Wees notoriously have a very poor grasp of the rules.  Don't let
them get away with it though, remind them--gently--that in the official rules
"this" happens instead of "that"!  Make sure you've got one of those rule
books handy so Mom can read it too.  Some Pee Wees take it personally when
they're wrong and then you'll never get that babysitting job!

    Now, you've just sat down with Pee Wee.  Her mom can be sitting in the
room too, but since Moms usually don't know ANYTHING about the game, your
obvious (to anyone familiar with the game) lack of sense while playing won't
make her feel like you're letting her little Pee Wee win.  If Pee Wee is
really that bad at the game, you'll probably have to adjust her deck before
the game... Like take out all those electric energy--she's using only water
and fighting pokemon--and make sure she added some potions.  Pee Wees seem to
like it when you almost have their pokemon knocked out and suddenly they whip
out a Potion.
    You have to attack.  Let me say that again.  YOU ABSOLUTELY MUST ATTACK!!
Even my 4-year-old brother can tell when I'm just letting him win!  You must
look (at least to Pee Wee) that you're trying.  However, don't use Ember, use
Scratch!  Make sure Pee Wee has a few pokemon on the bench before you hit
Staryu that last time.  If you have to, remind the kid that she loses if
there's nobody on her bench when the last one faints.  If Pee Wee doesn't
have anyone to put on the bench, swap your attacker for a staller, hopefully
your attacker has like a retreat cost of two or three!  Or bring out someone
without energy.  Or that poor 1-hit-left Abra you retreated in the hopes of
finding a Kadabra (wait, that's too strong, you didn't put it in the deck in
the first place!!)

    The lose-on-purpose game can be made easier on you (yes, you HATE to
lose, and it does YOUR ego a LOT of damage to lose to a 6-year-old) by
modifying the rules to a "quickie game" ... as in, only 3 prizes instead of
6.  Or if you're really good at losing (on purpose, that is!!) you can go
with a Sudden Death game.  Only one prize!  Then you can get the wretched
game over with, Pee Wee is happy, Mom is happy, and you're happy too because
now you can go beat Pee Wee's big brother with your *real* methods!  Boy
he'll be surprised when you use the same deck and whip him! (or if you
actually bothered to build a loser deck, swap the decks under the table while
nobody's looking!)
    Recap time!  (parentheses) indicate suggestions
        Do include:
                Cheesy basic pokemon. (magikarp, abra)
                Not-so-cheesy basics (charmander, ponyta)
                Some Stage 1 Pokemon (charmeleon)
                A few Stage 2 Pokemon (charizard!)
                Colorful Energy

        Do NOT include (or you can, and ignore or use lousy attacks):
                Trainers that are mean (gust of wind, energy removal)
                Fancy Trainers (like Lass, Scoop Up, Breeder)
                Strong Stage 1 and 2 Pokemon (hitmonchan, kadabra, gyarados)
        If you can help it, don't use holofoils.  Charizard is okay if you
bring it out against Pee Wee's water pokemon of any sort and don't attack ("I
don't have energy!!") 
                Kids love to win.  And Pee Wee will be absolutely thrilled
when she wins.  But don't let the kid win TOO much or Pee Wee's ego will not
match her nickname!!!!  The strategy I use with my Pee Wee is I lose about
half the time.  Sometimes you just can't help but win because Pee Wee refuses
to let you tweak her deck (to get rid of all of the Pikachu, evolutions
without the basics, and TWO GRASS ENERGY plus all of those useless trainers) 
*sigh*

            a dippy message from
        Rainy, the Furry Blue Mock Dragon