Another thing the IC isn't considering, whatever she makes from you (as an employee) will be MORE than what she brought home as an IC. Before I moved here to Southern California, I ran my own business for almost three years. I probably really only took home about 20-30% the total fee for a massage after paying business rent, bills, washings, advertising and so on.
Here, I work for a woman as an IC and she pays me 60% (which is really high for this area) and I take home the ENTIRE pay. The only thing I cover is my lotions, laundery and face cradle covers.
So, if the IC wants 70% and she is an employee, she will be taking home a lot more money than when she was working for herself. However, if you are supplying everything and all she has to do is show up, she should not be paid more than 50-60% and she will still be making the same as when she had her own business. (actual take home pay)
Or if you want to keep her as an IC, think about if that 30% will add up to about what you would normally charge for rent. If she supplies everything, then the 30% may be enough to cover your rent and bills---ONLY if she brings in good business.
Having an employee is more expensive and really a big headache. A friend of mine owns a spa and he recently changed his IC's into employees. The amount of paperwork he had to fill out was incredible and it ended up costing him more in the long run.
If you want someone who will do what you offer, then you should be able to find a massage therapist who is an IC who will perform those services. Just because a therapist is an employee won't make them any more reliable and you can still fire an IC just the same.