Yes, I can guarantee she had feelings for you.

She went as far as to specify that she wanted it to be just the two of you and your boyfriend could not come.

She's not mad at you because she thinks you're homophobic, she's embarrassed because in her head, even though it seems like you clarify that this was not a date, she thought of it as a date, hearing you clarify that it wasn't a day and even including the fact that you had a boyfriend hurt her ego (which is why she says that including him is a red flag) and killed any shred of hope she had that you two could start something.

Maybe she thought that if she took you on a nap dates, you would start gaining attraction to her.

Thats juat my theory.

she's turning that embarrassment into anger because it's easier to deal with and process.