I went to a support network thingy when froglet was about five months old. The leader put us into groups of three after introductions, and told us to have a five minute conversation, in which we were not allowed to mention 1. Our babies or 2. Work 3. Partners. We then had to report back.
And man it was hard! Those months of twenty four hour eating sleeping breathing baby had just wiped our brains, and EVERYTHING seemed to somehow link into the new off spring. We'd talk about family, say our mums etc and then suddenly the conversation would slide into "have they enjoyed being grandparents since the baby... Oh sorry..." Or "ok food and drink, I love white wine, but then again I haven't enjoyed a proper night out since the baby....oh sorry....
" Even clothes for heavens sake! We couldn't even manage that! It was "I can't wait to get my body back after the pregnancy .... Ah gadnamit!!!"
Conversation is something you need to learn again after having a baby I think. Op, was your friend good at anything like cooking before the baby came? Perhaps you could ask for her advice about a recipe or something? Even if she was rubbish at it, just something of a technical nature that would be difficult to veer away from. You could also try to keep her in track, when she begins to veer off, say hey that's great, so about that cupcake mix, do I add pecans? Not beandipping exactly, but just returning to the topic each time.