What's the price range you are looking for? I asked because I am also a mom (with a young toddler), I have used a few crossbody bags in the past 3 years or so, here's my recommendation:
1) Low-end: Rebecca Minkoff MAC (medium), Annabel Ingall Jojo crossbody bag (like a "inspired" version of the Celine trio)
2) Mid-tier: Chloe Marcie Crossbody (medium/large), Phillip Lim Pashli (small/mini)
3) High-end: Chanel chain around messenger (medium), Tom Ford Jennifer bag (medium)
I have owned and used all of them, my all time favorite is the Chloe Marcie Crossbody. It is durable, lightweight and surprisingly can fit a ton of stuff, very comfortable to wear crossbody without digging in the shoulder while carrying a toddler around. It is very understated also so you don't feel like you stand out at the kiddies park =)
It is priced reasonably for the functions/styles you are paying for, and they do go on sale (seasonal colors), I used this bag almost everyday for 2 years when my son was still a baby and it is still in great condition, low maintenance, as I always say - I don't need another bag to baby because I already have a baby lol
