It all depends...
It all depends on the person. I don't think you can classify the female species of being one thing or another. Every person is different, and there is no way to say one person is honest or not without having personal experience with that person.
There are certainly very faithful and truthful women out there, but at the same time, there are just as many unfaithful women who tell lies. Everything in a relationship boils down to the major issue of trust. If there is no trust in the relationship, it will have be a difficult relationship to sustain for the most part.
Trust is huge, else you find yourself doubting your partner, and this creates a whole lot of tension in the relationship. It’s not easy to trust someone, but without it, there is nowhere to go. I would say that women and men can both be unfaithful and not truthful, equally.
It is difficult to say that females are more unfaithful than males, or vice-versa. There is really no way to know those things beyond any reasonable doubt. You just have to take the risk and trust your partner, and over time a strong foundation of trust is built and it won’t be much of an issue anymore.