I bought an iPhone 11 recently and my mum is angry at me because of it. Is she right to be angry?

For the past 3 months, I've been using an iPhone 8. I then decided it was time for a new phone because I think that is an incredibly long time to have an iPhone. I've been saving up for quite some time now and I had enough money to purchase one. I bought myself a new iPhone 11 a couple of days ago. It's amazing! The camera is the best camera yet.

However, my mum isn't happy with me due to me getting the new iPhone 11. She thinks that it is a complete waste of money, and that the price of the iPhone 11 is criminal/daylight robbery. She then went onto say that I should've been saving up for things like helping her and my dad pay bills and stuff.

Is my mum right to be angry at this?

I sat on my phone and it heated up. Will this damage the battery?

I was using another phone and it wasn't hot at all and then realised i was sitting on my iphone 11.both phones in both hands made me realise the iphone 11 was way hotter than the xr i was using and i was using battery draining apps like snapchat on the xr yet it was not this hot.googled it and apparently temperature over 30 degrees damages phone battery and the iphone 11 was very hot like 37 degrees like my body temperature i guess… How much will this damage the battery? I think i've been sat on it for two hours… I'm so paranoid about battery life… Did i do something very damaging to the battery life?