When to get an ultrasound.

Wendy🌻 • Mommy to 4 sweet babies. 2 beautiful girls and 2 handsome boys. Baby #5 is a GIRL and due in June!!
My mom will
Be coming to Alaska from Ohio to visit me and her granddaughters. 
I can get an ultrasound when ever I want to.. The issue is the cost.. So I'm only getting one more because I've already had so many. 
Should I get the ultrasound whole my mom is here? I'm 24 weeks and one day when she gets here. And i be 25 weeks when she leaves. 
My question is when does the baby start looking More so like one parent or the other? 
And should I get it at 24-25 weeks or wait until later on. I just thought it'd be cool for my mom to see her first grandson in ultrasound. She's so amazed with 3D- and 4D she'd go nuts.