I did a lot of reading when Liebs was a baby, but he really didn't sleep and would have me up for several hours at night, so couldn't study when he was tiny. I went back to school when he was 2 to study chemistry. I dropped him at Nursery an hour early and used that time to study/write essays/do homework, I sometimes picked him up an hour late and used that hour too - I liked to leave when lectures finished and sit in the nursery car park and get my homework done. I wrote up lab work in the evening and at the weekend. I did get up early, as he did 5am wake ups some days. Waiting for him to sleep was never a sure bet either. He often went to sleep after me. Still does, sometimes.

Liebling likes us to "work together" now - so I can sit and write/type/mark and he will do the same. Or sit and colour. It's together time, that's what counts.

It really depends on the baby - I know some people who can study with a 4mo because they are "good" babies (unlike evil Liebling, who was clearly mugging grannies at that age - sorry, I have a bee in my bonnet about the word "good") - that is, they sleep in expected patterns, don't demand 100% attention during all waking times and are fairly calm - or will do alongside activities (so give them a crayon and some paper while you write and they're happy). But it does depend on the baby. While I could (and did!) read just about anything to Liebling, just so long as I was reading to him and holding him, others don't have that luxury.