To do this crazy sleeping arrangement

1, you don't have to sleep train her.

2, put her in a single bed with a bed rail.

Mines had a single floor bed with an extra high guard since he was 10 months old

This.

Not crazy. Just do it. Bolster with pillows in the double but use bed rails too. My DS had to upgrade from cot to toddler bed before 12 months so I understand why your DD may be unhappy in a cot.

I personally think 15 months is too small for solo sleeping in own room, but you’ve got an older child, so you probably know more than me, but I could never do “cry it out” method - it can cause sleep anxiety and actually reverse development for a period in tots.

I’d either do a floor bed in her room for her or have her in with you.

please don’t do cry it out. It’s so cruel. A baby who can’t fully communicate and relies on their caregivers for their needs, left to cry until they fall asleep from exhaustion, knowing that no one really cares enough to come to them, is awful.

I bedshare with my daughter who is now 2. We’ve done this since she was 5 months. Was the only way I got sleep and it works.

@PC7102 at 15 months an awful lot of toddlers can climb over the cot bars - and it's usually a higher drop down than if they are climbing over a bed guard (if the bed isn't one of those high divan style ones).
Like you say - there's different types.

Think it’s less of a risk as the mattress should go right up to the bars of the cot if you get one that fits properly and can’t really move around inside a cot. Cots should be high enough that a child can’t climb over and are wooden bars rather than material. I guess if the guard is fitted correctly, is the correct guard for the bed type and not made of material that can smother a child it would be ok but there’s so many different ones out there

@PC7102 but that can happen with a cot at that age though - couldn't it?

There’s a massive risk of entrapment with younger children, and also the toddler climbing over and falling.

Honestly just try anything that works and that means you don’t have to resort to letting your tiny baby cry it out. The cry it out method hardwires a baby’s brain for future mental health issues.

@PC7102 this maybe a daft question but why are bed guards dangerous for 15 month olds?

Yeah I'd give her my double bed and get a single for her room for myself. I'd swap rooms basically. She will need the bigger room when she's older anyways.

Whatever works to get some sleep, I'd do.

Do what ever you need to do to get some sleep (assuming it's safe)

Not what you asked but Dp was a horrendous snorer and it turned out he had nasal polyps, I do wonder how many snorers have them and don't realise

My son has never slept alone so since he was about 7 months old I slept on a mattress on the floor in his bedroom with him. If she will sleep in a bed alone then just get her a floor bed so she can sleep in a bed but won’t fall out. Just to note that stacking pillows around her and bed guards are not safe for a 15 month old

Or a single bed with a bed guard?

She doesn't need a single bed, is her cot a cot bed? They're quite low so if she fell out she would be fine. Or a toddler bed? I think it's safer than stacking pillows all around her in a double isn't it?

Can you get one of those 4ft doubles for her room if it isn't big enough for a double? All my kids have gone from sleeping in my bed with me to sleeping in their own double beds. Makes it much easier when we have visitors too.

Similar situation with cot hating. We did a 3/4 size mattress which took up the whole box room - stair gate on the door. Bed guard thing by the gap. Turned off the radiator. Sorted. Basically a padded cell. Kid loved it

TLDR, have you tried pool noodles? Put them under the sheets at the edges of the bed, it’s just enough of a lip to stop them rolling out without being a suffocation risk.

Do whatever is easiest for you all to sleep.
my son slept on a mattress on the floor from 11 months because he hated the cot. If he rolled off the mattress he didn’t hurt himself because it was only a tiny drop. Worked great for us but I’m sure some would think we were insane

Single bed with pool noodles under the sheet to keep him from falling out?

You'd sleep in a single bed in her room but a single bed won't fit in her room so she can't sleep in it.....🤔😕🙄

I'm with the single mattress team....other than that I don't get it....either you or perhaps I are sleep deprived and are making very little sense.

She’s old enough to go into a bed. Just buy a guard so she can’t fall out. All of mine were in a bed by that age

Mine were both in a bed by 18 months. Probably just over 13 months. They kept falling out but we had the cot mattress on the floor next to the bed to make it secure. We had to as they were trying to climb out of the cot and onto the chest of drawers near the cot. So it was safer for the bed. Toddler beds are quite low if you can get a full length single one but that is just a lower version. My eldest used hers until she was about 7/8. But it was full length.

Get a guard. Seems straightforward enough.