Yes wash the foot (well all four of them) in some warm water (and Dettol sounds fine for that), and then carefully trim the hoof (as in the nail bit). Don't do too much immediately, wash the feet first and see what is what. If it smells - that's foot rot. If the skin is raw and looks wet in-between her toes - that's scald. Not uncommon if the goats have been housed for most of the winter. If it is not too bad, you could use a Terramycin spray (blue stuff available from the vet's only) on the bad foot, and keep her on dry ground. Repeat a couple of times.
Re-check and trim a bit further every couple of weeks until it all looks fine, then every 4 - 6 weeks should be fine.
If you need some photos on footrot - googling it will show what it looks like. The smell is unique - you will know about it when you smell it... can't google that (yet)