When to move from cot to bed

[KipperTheFrog]

DD2 will be 2 in a couple of months. She's in a cot bed at the moment, sharing a room with her sister who is 4. Having the debate with DH as to when to move her to a proper bed. When she moves to a proper bed we'll put them in bunk beds with DD2 on the bottom bunk. This will free up a lot of space in their room.
We moved DD1 to a bed at 2, as we were going to stay with family and they only had a bed, no cot. Probably would have waited longer otherwise.
When did you move your toddlers to a bed?

When they climb out of the cot and are no longer safely contained

Dd was just 2 and Ds was 2 and a half

DD never tried to climb out, but she was 2 when we took the bars off and 3 when we got her a proper childrens bed.

My eldest was 18 months when she went into her bed. My youngest is just 2 and is going in her bed tonight as she has outgrown her space saver cot

DD2 is so tiny it'll be ages before she can climb out of the cot! She tries but just isn't tall enough.

Ds1, aged 2 years
Dd1, aged 18 months
Ds2, aged 15 months
Ds3, aged 2 years.
Dd1 and ds2 were prolific climbers.

I'm struggling with this myself. 2.5 year old girl who currently doesn't want to go to bed for the first time ever - I'm worried if we put her in a bed that she'll just climb out. How do we stop this???