That time of the season, all the local mountains (Copper, Keystone, Breck) usually have similar, somewhat-limited beginner terrain available. It should be perfectly adequate, however. If you were coming after mid-December, I'd lean toward Copper because, after that time, the Union Creek base area will be open and it's several miles of gentle, wide, user-friendly beginner groomers, segregated from the more-challenging parts of the resort.
She would be best-served in an all-day beginner group lesson, ideally followed by another day or two of all-day lessons (around $90 per day, or around $125 with equipment rental) to set her newly introduced skills into her muscle memory and build her confidence. Another alternative might be half-day privates. Ask if there is a discounted Beginner Lift Ticket. No reason to pay more for a ticket to access terrain she won't be using. Most of the mountains will let her continue with her first-day's instructor if she felt she connected well with him/her. You are wise not to try to teach her yourself. Divorce courts are filled with people who do so. Relationships bring a whole set of distracting emotions into play when one partner tries to teach the other.