My sister gave me a $100 gift card for a hair salon....

I wouldnt give it back. That can seem rude. Even thought you do your own hair, you could still use it (since it is a gift and you wont be spending your own money) this time and get a couple of hair cuts or something. See if they offer manicures or pedicures or eyebrows waxing, etc. After it is gone you can always go back to doing your own hair. You may like getting it done. It is like personal time to myself when i get to go to the salon. LOL
Maybe you could use it to buy some shampoo or hair products. That would go a long way for those. Take advantage of it and splurge.LOL
IF you choose to give it back maybe just say that you have been so busy and havnt had time to use it, and ask her if she would like to use if before it expires (sometimes they expire at certain places).

mail it to me (j/k) idk maybe she thought you'd like a day of pampering

Are there other services that they offer that you may enjoy, massage, mani, pedi, facial, for example. I too received one to a spa that I don't use. I may take my kids to get their eyebrows waxed. I haven't used it in 4 years, either. I agree and think salons are personal.

That is a very nice gift. I would not return it. That is rude, imo. Donate it to a women's shelter or one of those organizations that helps battered women get back into the work force.

I have mixed feelings about this. I can tell you that my mother has returned several gifts to me, and it made me feel bad.

On the other hand it shouldn't be wasted. Can't you use it for your kids or your husband?

You cut your own hir. I am impressed. It is considered rude to give back a gift. Yes.
Can you get your nails done or something else at the salon? Or is it that you do not wish to use a gift from her?

Wait for a day you can go out- they don't expire. May as well use it if you can't sell it since she wants to go with you

If she wants to go with you when you use it, I'm seeing it as she wants a few hours of sister time. If you really don't want to get your hair "done", you can still do other things and just get your hair styled. Go spend time with your sister and try to relax and enjoy the gift.

It would be rude and wrong to give it back. Make the best of it and use it with her, it would be a great sister bonding experience. I am sure that they do other services as the other said.