Hi again Maria,
I just mentioned the Manure/Compost subject in another post here.
These two words get thrown around and interchanged “willy nilly” as if they are one and the same thing and this causes confusion for many inexperienced gardeners.
Basically Manure is Manure until it is completely decomposed then and only then is it compost. I personally prefer to leave it to decompose for 2 years but others say 18 months whilst yet more will say 3 years! For me, I look to see if there is any trace of bedding and if there is none or very very little I use it.
As for your friends Herbs. The common Herbs we grow will survive perfectly well in most garden soils without the need for lots of fertiliser. Well drained reasonably fertile soil is all that is required for Herbs. If she is growing Mediterranean Herbs she needs to add lots of grit or horticultural sand because these herbs love stony ground.
Don.