Changing diaper?

So I’m just wondering how often you change your child’s diaper? My daughter is 3 months and and 2 weeks old and I change her probably 7 times a day not counting poops because she doesn’t poop everyday. My friend came over for about 6 hours and changed her daughter not once, I changed her daughter one time she had a VERY full diaper of pee. She complains about her daughter having spilled through her diaper almost daily and I now know it’s probably because she doesn’t change her often. This was the second time she came over and the first her daughter had pee and poo all up her back. Also her daughter is 2 months now.