I did 4 months old and work from home. Wasn't easy but possible. Taking care of kids 2 and 3 without help and working from home is practically impossible without something has to give.
Lots of juggling. I'm salary so I get paid no matter the hours and most of the time the kids are tied up in one activity or another. Not literally, though the thought has crossed my mind.....
I do everything on my laptop so I just sit in the same room with them and watch them play. They have a playroom so when I have conference calls they hang out in there.
The 4 month old is quiet and pretty much just sits there and hangs out. Sleepy dude too.
The couple down the street have an in-home daycare so once they become unmanageable I'll have to figure something out. That or get enough of a pay increase so wifey can quit working.