There's no doubt that the Queen of Winterfell was a frontrunner from the beginning when it came down to being voted number one mom. Like Cersei, she's super protective and truly wants the best for all her kids.
After Jaime throttles Bran out the window, who nursed him back to health? His mom, obviously. When Ned gets killed in King's Landing, what's the first thing she does? Tries to make sure her daughters Sansa and Arya are safe. She literally begged Littlefinger to keep them safe. She also helps her oldest kid Robb lead an army against the Lannisters before they all get murdered in cold blood.
The one black spot on her résumé is how she treats Ned's "bastard son" Jon Snow, who's not technically hers. Heck, she wouldn't even let him say goodbye to Bran before he shipped him off to the Wall forever. Bottom line: she treats him like complete garbage, and we're not OK with that, which lands her in fourth place at the end of the day.