Should we throw it away?

I have been caring for my 5 year old stepdaughter since she was 18 months old because her biological mom decided she wasn’t ready to be a mom. Recently she came back into her life. We just started allowing her to take her for the day.

When she brought her back to us yesterday she had a huge bag of makeup with her. She gave a 5 year old several eyeshadow palettes, eyeliner, several blush and bronzer palettes, lipstick, lipgloss, and a bunch of makeup brushes.

Now I do give her makeup brushes so she can pretend to put on makeup but no actual makeup. She’s 5... she doesn’t need to be wearing makeup in my opinion and in her dads opinion. And besides that we can’t even give her chapstick because she eats it and/or makes a huge mess with it.

We are trying to decide if we should just throw the makeup away. We don’t want to be mean but she’s 5... what is she gonna do with all this makeup? Opinions please!

Also: I feel like her mom did this because I gave her some makeup brushes a couple weeks ago. Every time I buy her something she has to outdo me. I bought her 3 books, mom got her a big book of 20 stories. I got her a package of chalk, mom got her 2 big packs of Playdo. I gave her some makeup brushes, mom gives her a big bag of makeup. 🤷🏻‍♀️🙄