Is it permissible to openly announce the engagement of a woman who is in her waiting period (iddah)?
It is not permissible to openly announce the engagement of a woman in her waiting period (Iddah), but it is permissible to hint (imply) at it if she is in her waiting period after the death of her husband. And Allah Knows Best.
Is it permissible for a person who has to make up for missed fasts to fast six days of Shawwal (the month directly after Ramadan) before making up for the missed fasts?
Yes, it is permissible for him/her to do so, but it is better that they make up for missed fasts first. And Allah Knows Best.
I`m in love with a certain man, and want to marry him in particular, but my family refused that, what should I do?
The father should know what is in the best interest of his daughter and consider her situation. On her part, the daughter should trust her father`s view point as far as suitors are concerned. Moreover, it is prohibited for any woman, or girl to get involved in a relation with a non-Mahram (Marriageable man).
Is Iddah (waiting period) incumbent on an old woman whose husband had died?
Upon the death of the husband, Iddah is incumbent on the wife regardless of their age. And Allah Knows Best.