Help!! I need some advice

I have a friend and let’s call her Ellie. Well Ellie sometimes comes round my house and my mum always offers food and goes out of her way to make Ellie feel welcome. In my culture this is a normal thing and she is of similar culture to mine. She will not eat at all round my house and it makes my mum frustrated. We don’t force her or anything but I feel like it is polite to even try. When she says she doesn’t want to eat it isn’t in a fussy way it’s more in an arrogant way. Once I told her that I wasn’t a massive meat person but would still eat it. It just so happens I was going to her house and her mum would be making meat and she said “oh well that’s what we are having” which I’m fine with it’s enough just being invited over. I’m quite a slow eater and her much asked me if I wanted more and I said no and she gave me a dirty look. Sometimes I’ll tell Ellie in advance what we would eat before she comes over and even with her approval she still refuses and states how other people make it better. In addition, sometimes I’ll be really excited about something and she’ll kind of just ignore it and not celebrate my successes. She’ll then compliment my other friend and say how she is amazing at something that I just did well in. Ellie also won’t really come out much which I understand she is busy but I feel sad that my friend won’t come out with me and cancel on me. I’ve also told my friend that sometimes I feel left out and she had previously said this and made a big deal but when I said it she just said “we all will at some point”. Aghhh am I overthinking this? The girl has been there for me through a lot and I love her but sometimes I find some of her actions I bit odd.