Did I tip too much?

So I usually go to this Vietnamese nail salon near me and today I went to take off my acrylics and get some gel nails done.
I’m 17 years old and my dad whom I rarely see gave me 40 bucks to get my nails done, I used my moms credit card incase I needed any more, so I got there and this man attends me, and starts making conversation asking me about my school age life etc, after a while because it took 2 hours for my nails to get done we started bonding as he has two daughters around my age. He tells me how he is a single father and just life stories and funny moments with his daughters. I really liked him and he seemed really genuine.

I asked for a French tip (which is 10) but he charged me (5) at the end the total cost was $51(which now that I think back on is pretty high) but yeah he asked for my name and seemed really nice so to return the kindness I gave him $15 tip because again he’s a single dad two girls like me and idk he was nice

But oh dear when I tell my mom she was shocked, to be fair iv NEVER tipped anything more than 10 but I was like oh well 5 more bucks, anyways she said that the gel manicure should’ve been 30 and that they charged too much and the guy was just hoping if tip more by gaining my trust since I’m young and that now everytime I go get my nails done they’ll expect 15 dollars which I only gave since I had the extra money

What do you guys think?