Midwest, not necessarily. Consider these points:
First of all, slonimer asked when it is appropriate to redt such a shidduch- it does not mean that the man in question is only looking for a single girl.
However, here are some reasons why he may want a girl who has never been married:
1. he is a cohein
2. Blending families, dealing with 2 sets of exes and the accompanying baggage can lead to a lot of strain on a relationship. He may feel that his second marriage may have more chance of success if his wife was not previously married.
3. There are a lot of older, single girls out there, maybe more than divorcees/widows, so why should he limit himself?
From the never married girl’s point of view, if she is older and been dating for a long time, she may feel that a divorcee is more “normal” than a never been married guy in his 30s or 40s.
To address the OP, it really depends on the girl and how willing she is to think out of the box, and how hard it has been for her in the never been married shidduch scene. Age may open her to the suggestion, but I think the exact age will differ for each individual. The only way to know is to ask what she wants, what she is willing to try- and to do it in a respectful, understanding way and not a pushy manner. She also may be more open to the idea for a specific suggestion that is very appropriate, rather than as a general, theoretical idea.
And yes, of course she needs to be careful and try to get objective info about him, and make sure he is not abusive or have psychological issues that can impede a marriage (and by the way, not-having-been-married-yet doesn’t guarantee that a guy doesn’t have those issues..). It will be helpful to her if you can provide as many answers and as much background as you can.