Intense feelings towards useless things

This gave me the most confusion in the ex relationship i read that they have very intense feelings but i’m not sure if this is a bpd trait.

She never did this before but when we were 2 years into the relationship she got a sick cat who died 4-5 months after she got it and she was hella sensitive about it and kept crying and literally cheated on me just because i didn’t give her the validation and empathy she wanted and then she even got a tattoo of the cat which was crazy to me because she had other animals and the cat didn’t really play a big role there because she didn’t even had it for long but thats not the only thing that happened

Her very very distant aunt died and she kept using it as excuse to be sad and depressed and when i asked her sister like what was the aunt to them she said they literally talked like 5 times in their entire life just very distant family but she kept gaslighting me and lying that it was something more also few other people died who were not really related to her and she was just crying and being depressed (she didnt even attend one funeral)

And all this didnt made any sense to me

Was this validation seeking or bpd trait or what was she trying to do ?