I think, in the madness of the crush, you're not thinking this through properly.
Think of the possible outcomes.
She might tell you that she's flattered, but she doesn't feel the same. That's probably the most likely. It is likely to lead to awkwardness between you, because even if you try to ignore knowing that someone has feelings for you, it stresses the relationship. She'll be making sure she keeps her distance, to avoid giving you the wrong impression.
She might not feel the same, and think it's best to distance the relationship out of commitment to her husband. In general, this is the right thing for a married person to do if someone else admits to feelings. It'd be the end of your friendship.
She might feel the same and suggest an affair. This is probably the least likely outcome, but it's possible. You'd then either be having an affair, or you'd have knocked her back, so she'd feel rejected and your friendship would wilt.
Or, she might feel the same, but both of you be clear that you want it to go no further - and in all likelihood, that'd mean that you'd need to distance yourselves.
You don't need her to confirm if there is chemistry - there might be chemistry for you and none for her, she can't tell you that. She can only tell you if she reciprocates, and if you don't plan on an affair, that's irrelevant. If you feel chemistry, and you're attracted to her, that's all you need to know to decide about your future. Regardless of whom you fell in love with, you'd need to end things with your husband and get a clean break before starting something new.