well, I know it isn't popular, but having my dcs co-sleep aged 4 would have killed me, as they slept ON me and then I couldn't move or sleep.
I think there are a few things that are important
- teacher is saying she is happy once there
- How long does it take her to settle? Is it a hand over issue or is she crying for 30 minutes (too long)
- How do they go in? Do they line up in the playground? Can you take her in 5 minutes before or 5 minutes after the rest of the class, directly into the classroom?
I would ask for a meeting, and explain just how anxious she is, and how distressed she is getting. They need to know this is a bit more that tears as she goes in. Then ask to come up with a plan together.
I would suggest you and she go in just before the rest of the class, you sit at a table and do something together as the others come in. Once the class are mostly in, and moving towards sitting on the carpet (or whatever) then she goes and joins them and you slip out.
A home/school teddy might help. DD2 often cried at drop off and hated the transition, she found it easier if she had something from home in her pocket.
A plan for playtime eg that teacher finds a friend for her to play with so she doesn't go out on her own.
many schools have a TA/support staff who run groups for children needing emotional support. Does your school have one, and could she do a bit of play work with dd to see which bit of school is causing the problem.
That last one is very important, it can be something totally random that causes the problem, eg she is scared of the toilets, or she got wet feet at playtime.