To do this crazy sleeping arrangement

Apologies @PrincessAnne4Eva I have to mention that I would find that combination of bunting (anything rope like that could get twisted round) and high up ‘scaffolding’ very dangerous.

Our bed rail is mesh so super soft. Ours loves sleeping against it. I think a double bed would be more dangerous in terms of falling out (especially with a wriggly sleeper), even with pillows.

The reason we got our floor bed like the one linked above is because DD was in the king size bed asleep and she rolled out, missed the pillows and bumped her head once, it was quite a nasty bump and I'd never recommend putting a little one in a bed that's a normal height from the floor, now.

We have a gorgeous "floor bed" which is still raised off the floor about an inch (so decent airflow under the mattress) and totally safe for little ones if they roll out in the night. And they love playing "house" in them: https://www.diy.com/departments/flair-canopy-house-woodeng-single-bed-frame-pine/5060482167450_BQ.prd
I know someone who has one of these for her 8-year-old, too, so they're long-lasting.

Honestly OP, just do what works for you. We’ve had all sorts of sleeping arrangements over the years based on the children’s needs, and it is no one else’s business (we never contemplated cry it out sleep methods as they were not right for us). Everyone being comfortable, safe and getting decent sleep is the priority.

My girl is a terrible sleeper, I thought I was a failed parent as she just never settled. To this day she wakes up (age6). At age 4 I gave up and got her a small double bed. After years of sleepless nights and near nervous breakdowns we were able to lie with her and settle her during the night. 5 mins and that was it. Back to my own bed. Sorted.
when my son arrived I realised I wasn’t such a bad parent as he sleeps all night on his own and always has.
do what works !

DD was in a trundle bed at 17 months. Bed was higher on account of the additional roll out bed underneath it. Just had that pulled out so she had a soft landing if she fell out.

Both of mine slept on futons from birth-when they weren't in our bed. I reckon that or a mattress on the floor is what you need.

My son slept from the age of 1 in a bed pushed against the wall and a bed guard in the other side.

Stair gate on bedroom door
Never fell out once.

I would do this:

DH in a double bed in bedroom 1
Me in a double bed in bedroom 2
DD (15 months) in a double bed/mattress in bedroom 3
DS (age 3) in a single bed in bedroom 4.

Cry it out is incredibly cruel and studies show it doesn't actually improve sleep in the long run. You could put DD in one of the double beds, either you or DH in a single in what will be "her" room, and then when she's 18 months she can go in the single with a bed guard and you/DH can move back to a double.

Do what you need to do, a good night's sleep for everyone cannot be underestimated!

Yanbu, if everyone getting a better sleep go for it.

If you end up uncomfortable in single bed before ready to move her then have a rethink but definitely do it initially.

A normal single bed will be perfectly fine for her age.
Up against one wall and a safety guard thing on the other side.
If it's a regular single and she falls asleep in one of the doubles the owner of that double at least has a proper bed to move to for the night.
Ikea beds tend to not be very high. Don't get one of those massive divan things and she'll be fine.

It's your house, your family, your life. There are no rules. Do whatever you want/need. You don't need anyone's approval, understanding, permission, or opinion!

Happy sleeping, OP!

Is there the option of a small double at 120cm? This is the size many universities have in halls. I would plonk the mattress on a low wooden frame (saw the legs lower) with low storage boxes underneath. There are plenty of mattress protectors and fitted bottom sheets at this size and keep a single bedlinen to go on top of it so it doesn’t swamp her. A single duvet covers a small double top nicely.

The next stage would be a normal toddler bed which comes with sides atleast halfway along. And is quite low to the floor .
Not an adult bed just so you get a good night's sleep

Life is too short to keep asking what should you do in your own home. Just make sure everyone is calm, happy and sleeps. We are not in your house, so it is not our business telling you

My son used to thrash about and wake himself up when he was that age.
We put a mattress on the floor and he slept better on that.
I wouldn't use lots of pillows though

I would do it but with a floor bed and sleeping bag while she's so little incase she fell out or ended up under the pillows.

My DS was a little spider monkey and used to shimmy up the cot bars and throw himself out from 9 months old, so I put him in a single bed and got side rails to stop him rolling out.

People are being bizarrely obtuse about @SnoopysHoose 's comment. 😄

You'll need to buy a single bed for her at some point anyway, so why not just get it now and use it yourself for the time being if that works for everyone. Doesn't seem that crazy if it means you can all sleep.

If you are the one dealing with night wakes then you keep a double bed. You may need at some point to actually be in the same bed if she’s sick etc.

The snoring husband - who is actually the reason for everyone sleeping apart and needing all four rooms to be used! - takes the single. That leaves the maximum amount of bed-hopping space available. He’s sleeping through all this? He doesn’t get a double room too!