I have the same name as my aunt. My parents never asked her. It's spelt the 2nd most popular way. She has a son with the name Louie and I have always wanted to name a little boy Louis. Ever since I was about 14. Pronounced Lou-ie BTW. However, as we share the same name (just different spellings) and I plan on doing the same for my son, do I have to ask?? Her son is obviously my cousin and he is 17 so probably not an issue at all. We don't see each other that much anymore unfortunately, but do still see each other.
As it's different spelling and you don't see them all the time I'd say no also keep in mind you can name your baby any name you want you don't need permission, you don't have to worry about pleasing anyone but yourself and the little one of course.
I think it depends on how close the relationship is, as well as how old the person is who will have to share the name. If they're a baby/toddler/child and they're a close relation, I think you ought to ask but I think it'd be wrong to use the name
If it's someone older and someone you aren't close with, then I don't think you need to bother.
I don't know that you necessarily have to ask but you can't just announce the name and expect no discussion between family members. I think I'd let your Aunt know in a heads up kind of way. My family would definitely inundate her with texts asking what she thought about it <yours may be more polite than mine>
There is something a bit odd about a repeated practice of your family taking her family's names and spelling them differently (better?). I don't think the fact your parents didn't ask means you don't need to -she might be really annoyed about your name and never mentioned it. Particularly the spelling thing looks like you are correcting her spellings. I don't know quite what to advise but I think it could cause offence and you should be diplomatic.
I think it would be a bit weird for you to be the 2nd lot of Hayley/Hailey and Louie/Louie in the same family! It's a bit much. I think you should ask your aunt first in this scenario and if she's ok with it then carry on!