What makes you think you will be a babysitter? Don't offer and it won't happen.

Anyway, I think it's great. Once everyone settles down and stops cooing over having a baby in the office, then the office will settle into a routine that accommodates a baby.

We have a small office of 10 people and babies, children and dogs are standard for us.There is a general understanding that if babies/children/animals get too noisy or unruly then they get taken out or back home. And mum (and in one case dad) has 100% responsibility for baby/child/dog. Unless they are on the phone or with clients in which case we all step in and help.

It's fabulous that your employer is happy to do it and I think it is the way of the future.