You are a very nice person to worry about this little girl.
I am another former parent group person and have chaired many committees including the fundraisers. We set a policy when the school opened- one fundraiser per year- it always does well, making $20,000-25,000. For those that choose not to participate, that is fine. We let parents know we were happy to accept a tax deductible donation, if they don't want to sell stuff. We also supported the student council kids in collecting school supplies for the needy, items for the military in Iraq, school uniforms for displaced Katrina victims, ect.
You shouldn't worry about your daughter feeling left out for not participating in every fundraiser. If you can afford it, sit your daughter down, decide on an amount you would like to donate for the year and write a check, tell her you are doing this in lieu of the weekly stuff that comes home. Send a note letting the PTA/PTO know what you are doing. It will be greatly appreciated, and most PTA/PTO prefer this because there is no product cost involved. Or tell her this year we are going to chose to participate in X amount of fundraisers you can pick which ones you want to participate in, but we are not doing all of them. Paying for a needy child's field trip is teaching her to help those that need it. Sending in money every time the school asks for it is teaching her mom can buy my way in to feeling included. (You can't pay the kids on the playground to include her) She needs to have strong character that is not attached to mom's wallet. Of course you should send her on the field trips and contribute to class parties.
My pet peeve is my daughters middle school(has no PTO/PTA) having carnivals, dances, etc. during the school day and charging admission, the school staff plans them. We can afford it but is is WRONG!!! My daughter has asked a few times if she can skip going and keep they money. I always let her if thats what she chooses to do(she said the lines are long and the actives stink). If the school wants to charge admission for something it needs to be done outside of school hours. We pay for field trips in our school, but the cost is usually $5-10. Only 2 have been more, $80.00 for a 2 1/2 day outdoor ed. trip, and $20-30 for a mock town the kids run for the day. Our property taxes are cheap so I do not complain.
FYI, there are also a lot of cheap people. My daughter had an exceptional teacher that stayed with the class for their fourth and fifth grade year. Most of the kids in the class were there because they requested her (more than 1/2 the parents in the grade did). We took up a collection twice for her. Once when her young, son, a Marine died and at the end of the two years to get her a thank you gift. 1/2 of the class parents gave nothing (same ones both times). You could assume they couldn't afford the $5-10, but several of them are my neighbors, they own boats, jet skis, motor homes, $50,000 vehicles, etc.
I hate to say it but it is parents that over indulge their child that make it even worse for the kids that can't afford it. Children need to know that not everyone is created equal some have money and others don't BUT education should be for everyone and if you include field trips as "education" ie as a school activity then everyone should go.
I have learned that one white blouse girls and one white shirt boys will work well if they share on picture day--we just adjust the size from behind with clothes pins--they look great in yearbook when they would have been picked on. I bring in all my "old" sneakers for the kids to use in gym. My first years of teaching I'm pretty sure I worked for a negative salary--thank goodness DH made enough to sustain our family. It took years to make tough choices like sorry I can't pay for your lunch if you are spending money on cigs! But I can't let a kid feel left out of a field trip or allow them to picked on if I can prevent it. Growing up is tough enough and the kids that don't have pretty much learn early on that the haves get more. My goal, get them to graduate, make better choices and take care of their own children well enough so that the cycle doesn't continue, but they need to be nurtured and to fit in so that happens. Sometimes it works and sometimes it doesn't, but I know I have done things to help for the right reasons and despite how much my career costs me, making a difference is priceless. DH tried to put his foot down and I took him to work with me for career day, when he saw what I was up against he just helped me make less work for more--the supplies on sale pre purchased, the one shirt for everyone rather than each getting a new shirt, etc. Taking turns for fieldtrips--they all don't need to go on all.
