Befriending Ahmadiyyah's and maintaining family ties with people involved in sin

Q: I have two questions: 

1. How to deal with people called Ahmadiyah? A girl was apparently wearing a hijab like Muslim women do and I grew friendly with her but now I came to know she is Ahmadiyah and not Muslim. What should I do?

2. How to deal with relatives who are involved in *gunnah e kabeera* or greatest sins. They also perform black magic and admit it. Is the prohibition of not cutting off with relatives still there for us? When these people also harm my family and try to create obstacles for every important thing.

The Hadith Regarding Nabi (sallallahu alaihi wasallam) saving a dua for his Ummat on the Day of Qiyaamah

Q: Is it true that when the son of Nabi (sallallahu alaihi wasallam), Ebrahim was ill, Ayesha (radhiyallahu anha) told Nabi (sallallahu alaihi wasallam) to use the du’aa that every prophet is given in which Nabi (sallallahu alaihi wasallam) said: I am saving that du’aa for my Ummah on Qiyaamah.

Repenting from making bracelets that have signs of shirk

Q: I made thread bracelets for a school project and my family. Since we’re from the subcontinent, amulets are common.

Some of my cousins asked for bracelets and I made them for their children to wear. I made for others but some of those people have moved out of the country and I am no longer in contact with them.

Also I had wandered into astrology and zodiac signs and stuff, discussing it with those around me including my classmates of which some are kaafirs and some Muslims. I did not know these were acts of shirk and most lasted from before to mid puberty. I don't know what to do so I can give charity on their behalf even if they are kaafirs since I'm not in touch with them.

Before I rarely prayed and fasted but now I know alhamdulillah I’m more practicing and have realized that the shirk I have spread. Is there a way to resolve the issue? I have no idea of their intentions and some are requesting bracelets but what should I say.