I'd say if she seems to be really uneasy (and you might not tell, most women will try to just be polite), you can try adding it in. Probably unnecessary if you've put the why's of it upfront, though. If she says no, you can always add a little more about what you wanted to talk about, and tell them the offer is open if she'd like. Well, in your own words, and using simlar language as you would with any other coworker and stuff.
If I were to speculate, I think some of this has to do with the way we treat dating culture and flirting - lots of hidden meanings and things that aren't/shouldn't be said instead of simply being upfront about intentions. If some of the courtship ritual were changed, I think there would be less ambiguity. I also think this has a good deal to do with culture and the messages we are taught growing up (for example, women being taught they should be suspicious of men's intentions, even though most men aren't assholes in that way).
In a way, your expressed difficulties are precisely the problem.
http://micheleincalifornia.blogspot.com/2014/03/the-gray-zon...
Focus on the topic, I don't know if that grey area can be solved any time. Whereas there are feelings there will be people incapable of control them. And I'm not talking only about romantic feelings, I'm talking also about fears, insecurities, pride... we aren't taught to manage them if it is not done by our parents and that's something that doesn't seem to be changed any close in the future. So, for example, there always be guys that will misinterpret women that are just simply being nice to them and women fearing or feeling being left out of the group when there is just the common behaviour between guys.
I have read articles about the problems created when men from countries where the veil is normal move to countries where it is not. For such men, who have lived their whole lives in a culture where women are covered from head to toe in public, it is a shocking level of nudity to see women with bare faces and exposed hair and bare arms, etc. For them, it is also highly sexually charged and they stare or make inappropriate sexual advances.
Western men are not shocked by seeing a woman's face in public and it does not strike them as inherently sexually charged. Yet, even western men (and women) tend to find it weirdly over intimate to really talk with members of the opposite sex and both men and women tend to err on the side of thinking it equates to being hit on. That piece can absolutely be changed so that it is much more normal to talk with people, regardless of gender, and not default to thinking it must be an expression of romantic interest.
I have literally spent my entire life working out another answer. I try to blog about that. I don't get much attention.
I think I have something unique to offer in that regard. I would sincerely appreciate it if I got more comments and I got promoted more by people in some way. Currently, it is mostly me posting my own writing and people largely ignore it.
If you want to see more constructive discussion and the spreading of the idea that, yes, things need to change without the subtext of because men are all rapey bastards and assholes, please consider leaving comments on my blog and sharing links to things you agree with on it.
Here is what I happened to have just finished writing when I saw your comment here, which I think I probably won't bother to post to HN because I am so frustrated with being ignored and with other aspects of doing that:
http://micheleincalifornia.blogspot.com/2016/09/change.html
Have a great day.
I wish it weren't necessary. Perhaps someday it won't be.
It really all depends on the situation and your current 'comfort level' with the person. I mean, if you've been working together some time and have chatted at the office, might not be an issue.
It might help to mention that you wanted to talk about work or their experience - This helps make it clear that it isn't a veil for a date (this is not foolproof). It might seem more appropriate to ask them to eat lunch with you in the middle of the workday, and things like that.
In other words, make it a coworker sort of thing, and use your judgement. Whether she declines or accepts, just go on and treat her the same nevertheless.