Re: 2yo DD Touching Lady Parts. .
In the op you didn't state she was doing it in front of people. In that case I would try to discretely divert her attention and not make a big deal about it. If she throws a tantrum, be firm and don't pay too much attention to it. Explain simply that this is not the time to do that. I feel bringing in the "ladies don't do that" part is unnecessary and may be harmful and cause shame in the future about sex. JMO.
Mama to 4 kids, DD 10, DS 9, DD 5, DD2