Wali of a girl whose father does not want to be present for the nikaah

Q: I was divorced 20 years back and I have 2 daughters from my first marriage. My parents brought them up without any help from my ex husband.

After divorce, he got married and I also got married. Now my first daughter is getting married. For some time my ex husband is contact with my daughters so she asked her father to be her wali in her marriage but he refused all of sudden.

My father, their maternal grandfather (nana) became her wali from the age of 2 since he only taking care of her.

My question is whether my daughter's marriage is valid or not?

Woman experiencing bleeding within 15 days after haidh

Q: Mufti Saheb is this correct:

1. A female bled for seven days. Her habit is usually 9 days. She again bleeds within fifteen days. She will count nine days as haidh from the first day of bleeding.

2. If she bleeds for one or two days, and then bleeds again AFTER ten clean days have passed (from the first day of bleeding) when must she count haidh from? (Will eight days be counted as haidh from the first bleeding day and the second actual bleeding will be istihaadha?

3. Will it change if she bleeds after staying clean for fifteen days?)

Marrying one's step sister

Q: My mother married a man aand they have a baby girl. After her husband died, my mother married my father then I was born.

Can I marry my half sister whose father is different and our mother is the same? We are both in love. If not, then what do we do?