Upload & Sell: Off
I've owned at one point or other all of the following: 20mm 2.8, 24mm 2.8, 28mm 1.8, 28mm 2.8, sigma's 30mm 1.4, 35mm 2.0, 50mm 1.8, 50mm 2.5, 50mm 1.4, 60mm 2.8, 85mm 1.8 and 100mm 2.8 macro.
If I was recommending for a friend of mine that recently had a baby, I'd go for the 50mm 1.4. 85 is going to be too long, and they already have a brother with that lens that they can borrow .
If it wasn't for baby portraits, but more to replace the zoom, I'd go with the Sigma 30mm 1.4.