I think my stepdaughters mom is an unhealthy influence on her morals, and I’m trying to undo the damage without throwing her mom under the bus. Advice?

I (26f) have a step daughter (6f)whom goes to her moms (31f) house every other week. (or at the moms convenience) A lot of ppl associated with the mother are burnt out on her. She is always showing off and bragging on fb (At least 3 posts a day) of new shoes, or new nails, new makeup, eating at a restaurant.. etc.. She has even asked my fiancé for money (in which he is the sole custodian parent), and will turn around and show off her $50 nails on fb the next day. (No he does not fall for giving her $) Anyway the mom has a house and car that was given to her by her mom, and over all she is entitled and spoiled with her hand always out. And after she does or gets something great, she immediately is seeking the next thing to satisfy her. Well some of these traits, I have noticed in my step daughter. If you buy her a pink teddy bear.. she wanted the blue one too.. she has had 3 backpacks this year. And now wants a 4th one. I told her most kids only get one backpack a year. Today she wanted to dress like a horse trainer for spirt week at school. Well we didn’t have a stuffed horse and knee high boots so she told me I needed to buy her those things and was grumpy. I redirected her and told her she won’t participate in spirit week if she is going to be upset over the “one day” we didn’t have the stuff to dress up. And just like her mom, we will get her a toy, then she says she’s bored, she will then ask to play a game on the computer, so I’ll set her up on a website and 10 mins later, she is complaining she’s bored. And so on and so on. Is this just something I have to sit back and deal with bc I’m just the step parent? I really don’t want my step daughter to be a high maintenance, ungrateful, hard to please, and complaining when she doesn’t get her way type of person. via /r/Parenting https://ift.tt/2Tkz69M