Yes, I highly recommend that she try some rental guns first.
There are tons of good revolvers out there. They come in all sizes and weights. S&W, Colt and Ruger are at the top of the list. But for something that she won't shoot a lot, there are other cheaper options.
There are tons of good used revolvers out there. Don't be afraid to buy used if you know how to check one over properly.
Generally, for a woman's home defense revolver, I recommend a medium frame revolver in .38 Special. The S&W "K" frames and similar being the perfect candidates. I try to stay away from the small framed guns. Especially for a beginner. Most find the recoil is too much and won't practice with them enough to learn to shoot it well. Large framed guns may be too heavy or unwieldy for them to shoot well. I've noticed that several people are recommending the S&W "L" frame guns. Great guns to be sure but they may also fall into that too heavy category for her. Same for the Ruger GP-100. However, some women will surprise you and take to a certain gun you never expected. So its best to let her try several and pick her own.