AITA for refusing to lend my money to my mom after my dad cheated and spent all their savings?

I am 20 year old and the only child I work 40 hours a week and I’m pretty decent with money I make a lot more than I spend so I have built a lot in my savings.I’m also leaving in my own apartment since I turned 18. My parents thanks to my grandpa who is very wealthy never had any financial problems they had a great house an amazing cottage and a lot of money to travel and spent in general. <br><br>I always felt like my dad was cheating. But I never mentioned to my mom because I had no proof. Well last week my dad cheated on my mom with his affair and got caught. The reason why I knew what happened is because his side chick is my friend thanks to my dad. She used to tell me about how she spent the money my dad gave her and I good friend didn’t ask questions as she is also my friend and didn’t want to bring it up. <br><br>Well she told me what happened and I told my mom. As my dad didn’t come home. She was devastated. But she used the phone and Laptop she found the receipts of the trips she found the emails the hotels etc. She cried for days. She was heartbroken and she asked me if she could borrow money to get to know how much is left thanks to the receipts. She was in tears and I felt horrible for her. But I was also angry and sad. I told her no. I told her that I am truly sorry but I won’t give her money I told her that I know he is her husband but I’m so angry and sad about this situation as she knew my opinion about him. She was mad at first but she understood me. <br><br>The thing is that my aunts and uncles are mad at me. They told me that I am a horrible daughter and I don’t deserve a mother like mine as I didn’t gave her the money. But I don’t feel like I did anything wrong. I feel bad but my mom kind of understood me.<br><br>Edit: Okay I will stop watching the comments as you guys are convincing me that I am wrong and I got my moms call to tell me how much money is left after they sell the house ect. So I think I will give her the money. And I won’t share anymore personal details. I also blocked my aunt and uncles on my phone. And good to know some people here actually have mothers who worked two jobs to make ends meet but whatever. Thanks for the awards it’s really appreciated. I also blocked my dad’s number and I’m thinking about getting a new number.