2. Can we proceed with our marriage even if the parents of this divorced woman especially the mother is against our plan ?(salam)

In principle, an adult female may marry herself without the consent of her
mother. If the Iddat is over, she may marry. It is not necessary for the
divorce papers to be finalized to marry.

However, it is best in the interest of the matter to discuss the matter with
the mother and inform her of her daughter's intention to marry anyway. We
suggest you do not hasten in marrying the person. You should make Mashwara
and Istikhaara if you are unsure, especially if you suspect her having
relationship with her ex-husband.

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai