I'm not expecting us to have a good winter, which is why I've kept my mouth shut, but our whole mountain (Whitefish for those using the Mobile version of the site) is below 7000 feet, so the altitude issue is close to nil. Before moving here I lived at sea level and on no visit here did I ever have altitude issues, unlike in Colorado, where I was miserable the first day unless I overnighted in Denver, and then spent another two days exhausted before I started having fun. That's a huge consideration if someone is pregnant and can't take medications.
We also have a great, real, town, with free shuttle buses between the town and the resort. Low crowds. Good value per dollar. (Ticket prices are in the low $70's, and a bit of research will reduce that further. For instance, if you buy the Frequent skier card ($50), you can reduce that to $46 per day. If you go to Costco, it's 2 for $101 or something.). Good restaurants in every price category. If it's another winter like last winter, you'll have 360° views at the summit. And the airport is about a half hour from town, at most, in fact getting lost. Takes me 32 minutes and I have to pass through town to get to my house, which is up a winding and ultimately dirt road. I'd recommend starting in town for the non-skiers to have easy window shopping. If there's small, skiing, kids, then at the resort. Either way, there's the shuttle bus to get to the other. Added advantage is it drops you off right at the base lodge.
As for terrain, it's weighted heavily towards cruisers, but there's a few cliffs and chutes for those that have something to prove, TONS of tree skiing of various densities, and the main lift has access to all levels beyond bunny. The 360° skiing means that you can usually find an aspect where the snow is what you are looking for, and we tend to move around the mountain as the day progresses.