Hi Kizzy
Firsty let me say well done on your first post, this is only my second post so i'm a newbie too!
I have worked as a nail technician in a salon for 6 years, 3 years into it a took the managers post and have been enjoying it thoroughly ever since. The main problem with renting a space once a week is that you cannot offer a reliable service to your clients. i.e, client has a broken nail mid-week, you are unavailable, what does the client do?
I suggest, when you talk to the hairdresser you ask her thoughts on this scenario. I would also be asking her these questions;
What do you expect of me? What should I expect of you? Will you be including nail services in your advertising, and will you expect a contribution? How many of your clients have expressed an interest in nail services?
Perhaps she would be willing to agree to a rent free period to help build your clientele.
What you could consider...
Working in a nail salon will give you experience in a reliable environment with help and advice always available. It can be rather daunting, but will allow you to find your feet. This experience will enable you to make a more informed decision regarding your future career path.
I should say, many nail technicians have found great success through renting a work space, but I would imagine, with no other nail techs around it could be tough starting out this way. Same goes for working as a mobile nail technician.
Good luck, i hope to hear how you get on.