AITA for not wanting my dad to walk my best friend down the aisle?

My best friend and I (both 23F) have been friends since we were about 3 years old. We have been through absolutely everything together, the good, the bad, and the ugly. Her dad has never been apart of her life, we have met him a few times but he overall sucks and is bad news. It has just been her and her mom pretty much her whole life, she does have other family but in general the whole family including her mom are a little nuts (but we still have love for them lol). I wouldn't say my dad raised her, but he has been the most stable and present male/father figure in her life.

Our relationship has been strained for the past 6 months or so, and we haven't really been talking, mainly because of an argument her bf now fiancé and I got into - that's a story for another time but it's important to note that alcohol was heavily involved on his end (I was sober), and I just in general don't love him but have always stayed cordial - My best friend and I were living together at the time of the argument and she's basically moved out since, she still pays her share of the rent but pretty much just lives with her bf now and we don't really talk anymore. I am not terribly excited for the engagement but have decided to move full swing into positivity because her happiness is really all that matters and she knows her relationship better than I do, and I am hoping maybe the wedding festivities will bring us back together, as we have been talking more lately since the engagement.

The other day my dad informed me that she had asked if he would walk her down the aisle, to which he said he would be honored. I am not sure how I feel about this though. Our friendship is not in the best place and I am also my dad's only daughter, his only little girl. My dad and I have gotten incredibly close as I have gotten older, and I so look forward to all of the father/daughter activities that come with life and weddings, and feel some type of way at the thought of her experiencing those special moments with my dad first.

My dad said he wouldn't do it if I wasn't comfortable with it, but I am worried I am being selfish in not wanting him to walk her down the isle, as they do have their own sort of father/daughter bond themselves. They just got engaged and they haven't set a date or anything yet, so the issue at hand isn't terribly pressing, but it has just been on my mind since he told me that she asked. What do you think? Any advice?