What age did you let your child play alone stairs lone

[Poolbirthx2]

My dd is 4 years old and loves playing in her bedroom. I also have 12 week old. Dd is happy to play in her bedroom alone as it sometimes hard for me to sit upstairs with her, for example feeding baby, baby is asleep! My question is, is she too young to play alone upstairs? I leave the door open and can hear her playing and if she goes quiet i will shout up or go check on her!

I leave my 2 year old downstairs when I scoot upstairs to get changed etc. If she wants me she yells or comes to find me.

4 should be fine surely.

I think that is fine. She is in a safe place and you can hear her.

My 3 year old plays upstairs in her room. With the door open I can always hear if there is a problem

My 1 year old plays by herself in her room sometimes (only for a few minutes at a time)! It's completely baby-proofed and has a safety gate on the door, but it's the only place I can leave her if I have to get something done, like have a shower...

I think 4 is fine. It may be a good idea to put a lock on your bedroom door so you know she's not in there. It comes in handy when they get older