I just went through this in the fall. My newest LO was 5 weeks old and I also have a 4 & 8 year old. I had 3 DC children return (3-1/2, 3 & 2-1/2) and had 2 new families start after 4 mths. You just have to manage your families expectations and there may be days where it is a more relaxed free play, movies etc. I chose to go the local early years center 3-4 times a week because #1 I was able to be mobile and #2 it was a great distraction for the children (mine included). My LO is now 8mths old and I have 5 full timers and my 4 year old is here every other day. Our days are crazy, busy and so fun and I wouldn't change it for a minute (even the exhaustion)!