@kickycan,
I love the tee shirt idea. It could be really funny. I can see all the kids wearing one ...maybe all the same "Dad loves me best" or , "Dad's favourite" something like that. A funny one just for your mom and maybe a few others for friends, grandkids (grandpa's princess) or some such along the same theme.
Hokey? You bet! Hilarious. Fun! Wish I'd thought of it for my mom's 80th.
Everybody wearing "Damn, You're 70?!" "Where's the scotch?!" or some variation sounds great to me.
Have a blast kicky.