Old car given as gift

My mother in law is giving me her old car to have its 35 years old I dont have a car she wants me to use it as a starter cus I have 2 small kids I think her daughter will be mad but my husband said I will need it more the daughter has a car her partner has one together with her. Only thing is cars air conditioning is broken for a while now and husband said it's ok will work for fall and winter. Car passed inspection. I never had a car but I can drive it's because I moved states and got married when I was young and never had money to buy one. So the car will b paid off it's a free starter car. My sister and mom got mad at me saying oh nice my mom got her a new car a few months back. But their also in Europe together enjoying life I'm home with my kids. What's better to get more confident in driving someone giving u their old car or getting urself a new car?