Sleeping arrangements for 2 kids

Hi, I live in a 4 room hdb but I converted 2 rooms into one room (mbr + study) combined. Currently my helper and 1st kid are living in the other bedroom. I am thinking of having a 2nd kid but not sure how the sleeping arrangements will be. I plan to get the newborn to sleep with the helper, so my older kid (around 2 years old by the time the 2nd kid is born) will either have to: - move in to sleep with me - get all 3 of them to share room (helper n 2 kids) - add a glass door partition between my mbr n study and get my first kid to sleep there Any suggestions? Thanks!