Blackout blinds - Why do you need somebody to make blackout blinds? Can't you just buy a ready made roller blind one from John Lewis, etc and cut it down to fit? Very easy!
Children's curtains - We recently paid £200 for a pair of children's curtains with blackout linings. They were beautifully made, to fit a curtain rail 140cm wide and about 140cm long. The fabric price was £9.95/m for 137cm wide. I would say that a pair of curtains would take the best part of a day to make, but I'm not very speedy.
Romans blinds - Roman blinds are a lot of work to make, so although they are smaller than curtains, there is generally more time taken to make them up. 6 is a lot! I would say that each blind would take me the best part of a day to make, but you'd maybe get quicker if you were doing 6.
Roller blind - again, can't you just make this yourself using one of the kits from John Lewis or similar? It is really easy and so rewarding!
So I think, if your friend is just averagely handy she could be taking on a week's work for you. But she may be much quicker than me!