When my daughter is sick we put a cool mist humidifier in her room. This helps a lot if she is not drinking as much, has a cold or a fever. The noise also seems to calm her. Before we got the humidifier I would boil water in the kitchen which is next to her room and that worked too but made the whole house humid.

If she wakes up at night we do everything we can to make her comfortable again such as change her diaper, offer her something to drink, cuddle her, and if nothing seems to work we give her some medicine and that seems to work most of the time.

Hope you find some relief soon.

Has she had any children's paracetamol or ibuprofen? I usually find these are very effective at helping my children to sleep when they are unwell, I suppose they are no longer feeling uncomfortable so they can sleep as usual. Ibuprofen seems to work faster. One dose usually seems to work for about 3 or 4 hours, by which time they are fast asleep, often that will see them through at least until the early hours.

It sounds like she is not really falling asleep. I agree with Meg Stephenson about giving Ibuprofen or childrens Paracetemol to sooth any discomfort (also if this has been recommended by your doctor)

When my daughter was ill I used to comfort her in my arms until she was absolutely fast asleep. I did this because it seemed to soothe her, and I felt better knowing that. Then I would put her to bed once she was totally asleep. The comforting, helps them relax more I think, and in turn this could help them nod off into a deeper sleep.

I still do that now, if she has a cold or feels unwell and feel that it helps. Maybe you could try that and see if it works for you.

Additional note: There are some really wonderful answers about co-sleeping here. I really feel that a toddler not feeling too well, would benefit from being in his/her parents arms / or sleeping next to them.