I went to Catholic grade school from Pre-K through 5th grade. This was a mistake, but only because the local public schools were of an extremely high quality and I probably could have gotten the same, or better education for free. I assume that isn't the case for you though.
As it stands I don't feel like the Catholic religious education hindered me intellectually- at least where I attended they didn't actually try to give us evidence or arguments for why God existed: they just taught us what we were supposed to do. Stand, kneel, stand, kneel, sit, kneel, stand. Don't use God's name in vain. I did First Communion and First Confession. Don't hit people or talk during class. I was very good at all of it. (I guess because I was such a good kid compared to my classmates I was pretty sure I was going to be canonized. I did think I might be like St. John and have the power to stare into the sun- which was almost certainly a risky thing to believe... end digression)
I don't know if I wasn't 'talking' to God enough or what, but as soon as someone presented me with the option of not believing in God I became an agnostic. I suspect if you instill her with rational, scientific values in addition to what she gets at school the Catholic thing won't stick. But keep in mind that I got out just before 6th grade. I'm not sure how things would have proceeded had I stayed. I don't know what exactly the Catholic church teaches adolescent girls but it can't possibly be that healthy so you may have to work to counteract that. I left because the small class size became a negative-- there were only 6 other boys and after my less popular friend left I was at the bottom of the pecking order.
As for the weekly mass, keep in mind that Bible verses are pretty much impenetrable to kids (at least they were for me). The only part of Mass I could understand was the Homily- and even then I usually drifted off. Most of religion class consisted of memorizing prayers and stories- Adam and Eve, Noah, the story of Christmas, the Stations of the Cross etc. Useless stuff but nothing really harmful. I never went to Sunday school so that might have undermined the indoctrination-- only a few of my classmates attended that. Most of the outside-of-school socialization consisted of CYO sports, which the entire class signed up for.
Oh, and obviously if you have any boys coming up don't let them be alter-boys or spend any significant period of time with priests. That's not even a cheap shot.
I've long entertained a dubious regard for the practice of lying to children about the existence of Santa Claus. Parents might claim that it serves to make children's lives more magical and exciting, but as a general rule, children are adequately equipped to create fantasies of their own without their parents' intervention. The two reasons I suspect rest at the bottom line are adherence to tradition, and finding it cute to see one's children believing ridiculous things.
Personally, I considered this to be a rather indecent way to treat one's own children, and have sometimes wondered whether a large proportion of conspiracy theorists owe their origins to the realization that practically all the adults in the country really are conspiring to deceive children for no tangible benefit. However, since I began frequenting this site, I've been exposed to the alternate viewpoint that this realization may be good for developing rationalists, because it provides children with the experience of discovering that they hold beliefs which are wrong and absurd, and that they must reject them.
So, how did the Santa deception affect you personally? How do you think your life might have been different without it? If your parents didn't do it to you, what are your impressions on the experience of not being lied to when most other children are?
Also, I promise to upvote anyone who links to an easy to register for community of conspiracy theorists where they would not be averse to being asked the same question.