If they have been seeing each other for about the entire year or a good chunk of it, and these "gifts" have been spread out over the year, I don't think it's some big odd issue she is giving gifts to your partner, and you/your daughter.
If you don't feel your family can afford gifts right now, I would just ask my husband to explain to his girlfriend that family finances need to come first, and while he does not mind getting presents, it isn't financially practical to purchase things for other partners (and if he hasn't been giving her things this whole time, they probably already have that understanding).
My ex-husband's girlfriend who I have met a few times now, has gifted me with a couple of pieces of jewelry (though she is a jewelry maker) I feel a bit awkward about it, and I can't afford to get her gifts, so if I'm ever in a position to give her a ride to the airport or babysit her son someday, I will pay back her kindness that way. I know she has done what she has because she thinks I'm nice, wants me to like her, and she wants me to know she appreciates how important I am to him and wants to recognize that by treating me like family.
So if these gifts are making you uncomfortable, you could ask her, or ask your husband to ask her - to refrain from giving you gifts because you have guilt issues/discomfort/whatever about getting presents when you aren't giving them in return. I don't think it sounds like there would be any benefit to asking her not to give your husband gifts though. I think if you are uncomfortable with your daughter receiving presents, you should talk to your husband about that and make an agreement together. It can be embarrassing talking about financial limits with partners, but if it is what it will take to make you comfortable, it's smart to do so.
Unless there is some reason to think she has said or done anything with gift giving to try to "win" your husband over, I don't know that there's anything wrong with anything she is doing. If she ignores requests to stop sending presents to you (and/or your daughter), then and only then is when I'd consider it a problem. She can't know she is making you uncomfortable if nobody tells her. She probably just thinks fondly of you because your husband talks about how awesome you are, and for all you know she gives you gifts because she thinks it'd be rude to give them to him but not to the other members of his family.
My husband loves buying gifts too. A part of every vacation from the first one on involves some shopping for presents for past and current girlfriends of his. He keeps buying me things even when I beg him not to, because he gets joy out of it even though getting gifts makes me uncomfortable. (2nd the Love Languages book's discussion about it.) His main motivation is to let people he cares about know that he's thinking of them, and to make them smile.
On a last note, she does exist, and if you can find some ways to figure out some positive but reasonable ways to incorporate that idea into your life (yes, a hundred Facebook likes would make me want to ditch a FB friend too), that would probably be beneficial too for you. Not saying you should force a friendship if you're not interested of course. But just remember there's a few good poly books that discuss dealing with feelings like this in detail that could be helpful.
Happiness will never come to those who fail to appreciate what they already have.