tell your agent, you are waiting for others reply, hope he gave you one week to think about. Or if you can't make sure how he is, ask him may he give you one week to think about it, or what's the expired date of that offer, you need to discuss it with your wife, becaue your baby is so small :-)

By the way, 我没有遇到完全类似的情况，所以以上只是个人观点，不过你的观点听起来也很personal :-)