"Marié" is the masculine form of the adjective; "mariée" is the feminine form. So you have "une femme mariée", but "un homme marié". There is no difference in pronunciation; only in spelling.
"This woman is married" ("C'est femme est mariée") and "this is a married woman" ("c'est une femme mariée"), while giving the same objective information, are still different sentence forms. I think if French didn't have a specific word for "is" ("est") or a structured way to differentiate these two forms (which it does), then you would be correct -- but being able to translate nuances like this important to learn!
Small correction: "This woman is married" would be "Cette femme est mariée", not "C'est femme est mariée".
Any time you have « il/elle est + modified noun », it is realized as « c'est + modified noun. » Determiners, like the indefinite article un/une, are modifiers, so you have to say « C'est une femme mariée. » And the same goes for plurals: "They are married women" is « Ce sont des femmes mariées. »