We have three boys, all 4 years apart...now ages 19, 14, and 10...not babies anymore...
When our 2nd child was born, we had the kids share a room from day one...we had no other bedroom available...at night, we kept the baby in our room, so I could breast feed him without waking his older brother...but at age 4, the older brother was old enough to understand that he had to be nice to his baby brother...
By the time our 3rd son was born, we had a bigger house, so we put the baby in his own room until he was out of his crib...then we gave the oldest son a room of his own, and moved the younger two in to a room together...
I think it is fine to have them in a room together if you don't have any space available elsewhere...is your 2 year old a sound sleeper? If not, the baby's crying might wake her. Is the baby a sound sleeper? If not, your 2 year old could wake her....however, they will get used to each other's noises and learn to sleep right through them...hopefully...
When ever you decide to put them in the same room, there will be a time of adjustment for both of them...getting used to the noises that the other makes, etc...when that day comes, put the younger child to bed first, and give her a good 30 minutes to fall asleep before putting the older one to bed...this will give you some time for undivided attention for the older child after the baby is in bed...something that will go a long way in the girls' getting along in the future...making sure that they each get the attention that they need...it's hard when you have a baby to give equal attention to the older one...but important.
During the time of adjustment, if you are worried about the 2 year old throwing things in the baby's bed, take away anything in the room that, if thrown, could hurt the baby...
Good luck...just wait until they are teenagers...LOL...Becky
