Daughter (20 mo.) wants to sleep in her brothers (3YO) bed... this is ok, right?

My son has slept like a champ since birth: All night, no getting up, bed at 7p until 6a daily. My daughter, on the other hand, co-slept with us because of breast feeding until about 3 months ago. Since then we had her sleep in her crib alone. My wife and I slept on the living room floor because she would cry and cry if we were in the same room (two bedroom house.)A month or so ago she learned to get out of her crib so we bought a captains bed and moved them into the same room and are expanding our house for a new master room for us. She doesn't want to go to bed at 7 like my son, so we moved bedtime to 730 which didn't work. Now it's about 830 and we try to run them around the back yard to tire them out. They still don't fall asleep right away and end up playing/giggling until they fall asleep in the same bed. Is this ok since they're still so young? I just don't want to develop anything bad.TL;DR: Son and daughter fall asleep in the same bed...ok or no? Sorry for the long winded post on a boring question. :) via /r/Parenting http://ift.tt/2aiGT0A