Unless she prefers a really long ski (and knows it and has skied skis that were new within the past 3 years that were very long), I would recommend the 162cm (162 and 170 are the only ones in stock). It goes more by weight than height. Although she is very tall at 5'10", 145lbs isn't very heavy. I am 5'5" and last season i weighed 140-145. I only skied the 154cm because that was all we had at the shop, but I would have liked the try the 162cm (but we didn't have it). I loved the ski Intermediate/expert isn't clear. Maybe you mean advanced? It is between intermediate and expert and it is what I am. I would recommend the 162cm. I would only recommend the 170cm in this ski if she was very heavy or a very strong skier who doesn't like short skis, or a combination of the two. I ski all different skis in different lengths. I ski longer skis and shorter skis. I can do this because I work at a demo center, but for buying a ski for everyday use, I would go on the shorter side, at least for this type of ski. Very few women like long skis. If you are concerned about the 170cm being too long for her, it probably is. Go with the 162cm. I see few women skiing on long skis (I live in the east, people probably ski longer (and wider) out west). For me, I prefer the 154 length, even though i usually like a slightly longer ski (156-160). I am sure that at 5'10", your wife has longer legs than me and will be able to ski a longer ski at the same weight as me, so I would recommend the 162cm, but not the 170cm. (I know that I probably repeated the same thing over and over again).