Yes, women are open to dating guys within this age range.
Women in their early 20s in particular may be attracted to men who are relatively older because they have only recently come out of their teenage years where they most likely dated guys who didn’t measure up to them in terms of maturity or even direction.
Keeping this in mind, it is not uncommon for women in their 20s to choose to date guys who are 5-7 years older than them.
Yes, it is true that a woman can break her own rules if she is really into someone. This often happens because of life experience.
As a woman matures, the same rules she once had and has tried to hold onto may start wilting as she is exposed to more and more different kinds of people.