if my friend who is qaddiyani become muslim,can she live with me and my family,infact my all brothers are younger?and can i make friendship with her[qaddiyani] to convince her to be muslim?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

It is an obligation on a Muslim to be keen on calling non-Muslims to Islam, and he should treat them well in order to soften their hearts towards Islam but he should not love them or be an ally to them. For more benefit, refer to Fataawa 90486 and 86169.

If your friend becomes a Muslim, then we congratulate her for doing so, because Islam is man’s greatest success in his life, as by being a Muslim he will lead a happy life in this world and he will be saved from Hellfire in the Hereafter. Congratulations for you as well if you are the one who guided your friend to Islam while having a sincere intention for the sake of Allaah because whoever guides people to do good, he will get exactly the same reward as the one who does that act of goodness, as narrated in some Prophetic narrations.

However, it is permissible for your friend to live with you if she is safe from mixing with non-Mahram (marriageable) men, or them seeing from her what is not permissible for them to see from a non-Mahram woman. As regards your small brothers, if they have not yet reached the age of distinction, then it does not matter if she uncovers herself in their presence. However, if they are above the age of distinction, then those of them who have reached adolescence, they should be treated like adults and she should wear Hijab in front of them, and they are forbidden to look at her. Those who are below the age of adolescence, she should behave with them like her Mahrams, in which case she can uncover in front of them the parts of her body which she uncovers in front of her Mahrams.  For more benefit, please refer to Fatwa 85449.  

Allaah Knows best.