Assisting one's drug addict father in fulfilling all his halaal needs

Q: My children's father is addicted to drugs. 

I do not feel comfortable with them spending time in his company & I'm advising them to help him with food only if he gets sick as I feel they are enabling his habit. He manipulates them to feel sympathy for him & uses them for money, transport, food etc. Am I incorrect for doing this?

Giving the value of mahr faatimi when paying the mahr

Q: I got married approximately 9 years ago. At the time my wife and her father wanted Mehr e faatimi as mehr. However I could not afford the mehr e faatimi at that time. They then agreed to a lesser amount but I told them that insha allah one day when I am able to then I will give her the full mehr e faatimi amount. This was just verbally said and was not written down. 

Alhamdullilah I am now in a position where I can give her the full mehr e faatimi amount. I would like to know if I should give her the mehr e faatimi amount at that time (9 years ago) which was approximately R 12 500.00 or should I give her the mehr e faatimi amount of current value which is approximately R28 000.00?