My mother thinks I'm wrong to try and get my 1 year old to sleep in his own cot?

My son currently sleeps the majority of the night with me and my husband. He starts off well but he's not good at settling himself back to sleep in his cot.

My plan was to introduce a comfort object such as his favourite toy each night to help make it easier for him to settle each night.

My mother is under the impression that I'm wrong to have him sleep in his own cot in his room next to ours. Even with a video monitor on full blast and all the doors open each night. She says he won't sleep by himself until he is 3 years old?

My son also doesn't sleep through the night and never has (he's now 13 months). We've accepted this now, so it's not an issue. My mum also says he won't sleep through the night at least until he's 4 years old.

Am I doing something wrong for wanting my son to have his own space to sleep now that he's getting bigger?