Different names for grandparents?

I'm looking for suggestions of different names for grandmother figures. Here's the back story on my weird family situation. My mother passed of cancer 4 years ago. More than anything she wanted a grandchild so it breaks my heart that she's not here right now. My mother in law also passed of cancer 2 years ago. A year or so after my mother passed away my dad started dating my aunt (my moms sister). I'm hoping to find a name my child to call my aunt that's better than him going around talking about grandpa and aunt Lynnie (which I call her) it sounds weird when your kid is talking about his aunt and grandpa being a couple. I'm hoping to use something that isn't grandma or memaw (that's what my mother in law wanted to get called) so what do you have for my train wreck of a family situation? 😂