How should he tell her that he wants to marry her?

How should he tell her that he wants to marry her?

I was recently informed of this site, ma'shallah. What is the correct way to approach a sister whom you intend to marry ? I've known this sister my entire life, in the same regard as my own blood sister and recently it was brought to my attention that she would be a perfect candidate for marriage. I believe she respects me, but I am unsure if she can accept me as her spouse. How can I know ? And what is the correct, halal way to approach ? I have nothing but the best intentions, yet my entire life I always felt I would marry her, yet out of respect I have never approached. My father and aunt (my mother has passed, allah yarham ha) are very fond of her and encourage me to pursue her, since they know her and her family extremly well.

 

Praise be to Allaah.
 

 

If a man feels that his heart is inclined towards a
particular woman, he should follow the way that is permitted in Islam, which
is marriage. If a person intends to marry a woman, he has to propose
marriage to her through her wali (guardian), who is her father if he is
alive, or one of her other close relatives.  It is not permissible for a man
to propose marriage to a woman who is not his mahram through ways that are
not permissible according to sharee’ah, such as getting to know her or
meeting her frequently or getting in touch with her often and speaking on
the phone; these are means through which Iblees causes people to sin and
which lead to regrettable consequences. It is not permissible for a person
to justify his relationship with a girl by saying that she is like his
sister and other silly excuses. You have to follow the proper channels as
prescribed in Islam to marry this woman. When you propose marriage, it is
o.k. if you try to win her over by giving her a gift through her wali. We
ask Allaah to give us and you strength and to keep us away from haraam
things. And Allaah is the Source of strength. 

See also question no.2572.