Honey, lemon and ginger is my stock remedy for this.
Get some thyme honey and some root ginger. Thinly slice/dice some root ginger, put into a teapot, pour on boiling water and *put the lid on.^ If you don't have a teapot, make it in a mug but be sure to cover it with a plate or saucer, or you lose the volatile oils.
When it's brewed for 10 - 15 mins, pour into a mug (about two thirds full), stir in a big teaspoon of honey, and squeeze in the juice of a lemon. Drink as hot as possible.
The honey soothes the throat, the lemon gives vitamin C and is antiseptic, the ginger is warming and expectorant. It's a pleasant taste too.
Sage is a fantastic herb for anything to do with the throat, but it tastes fairly antiseptic, as does thyme. If your daughter will drink it, you could give her (and yourself) sage tea; pick some sage leaves (or use dried from the supermarket), using a teaspoon of dried per mugfull of tea (more of the fresh), pour on the boiling water, cover it and steep for ten mins. Same with thyme.
Hope she feels better soon. 