It's kinda confusing because, if spoken, it could either mean "the woman understands" (yaj be') or "she does not understand" (yajbe').
When spoken, the stress and cadence are different. But I agree, it could be confusing.
Might be different. Might be the same, especially if the speaker is speaking at normal speed. But this sort of thing happens all the time in any language, and listeners will usually pick out the right meaning.