Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
For women who have reached the menopause age, the waiting period (iddah) after divorce shall be three lunar months starting after the pronouncement of divorce. Almighty Allah says in the Quran what means
“As to those of your women who anticipate no further menstruation- if you are uncertain [as to their term]- then their waiting period shall be three months, [just] as it shall be for those, who have not [yet] menstruated.” (Quran 65:4)
Allah Almighty knows best.