When my daughter was 3.5 going on 4 yrs. old , I bought her these pretty, plastic, adjustable, Barbie roller skates. She wanted to learn how, but I was not a good teacher. I can barely walk on my own two feet without tripping. It took her some time to get the hang of it, with no help from me and sooner than I knew she was skating! My husband wants to take my 2 yr. old ice skating. He says lots of them learn at 2. I am fine with it. I did teach my daughter how to ride a two-wheeler(bike minus training wheels) at four! Kudos to me for being able to contribute to my daughter's childhood. My point is they learn and know so much more than we give them credit for. If she really wants to do it, why not. If she falls it is part of the learning experience.
Oh, the skates I bought for her, I found at Toys R Us by Fisher-Price. I also had her wear a helmet and knee pads. Hope this helps. Good luck in what you decide and have fun.