Is my mocking my friend after an incident that occurred with her, and wishing for her husband to propose to my sister, considered envy of her?

What you suffer from, in terms of jealousy and malice, stems from a weak certitude and a lack of contentment with Allah's decree. If you were certain that all matters are in Allah's hands and that He distributes provisions with wisdom, Satan would not have incited you. You did well in supplicating for your friend and concealing what was in your heart, but ridicule is forbidden.

There are six reasons for envy: arrogance, pride, fear of losing what is desired, love of leadership, wickedness of the soul, and malice. Envy has four levels:

1. The envier wishes for the blessing to disappear from the envied, even if it does not transfer to him (this is the utmost wickedness). 2. The envier wishes for the blessing to disappear from the envied and to transfer to him (reprehensible). 3. The envier desires a blessing like it, and if unable to attain it, he wishes for its disappearance (contains both reprehensible and non-reprehensible aspects). 4. Ghibtah (envy without malice, or emulation): This is when one desires for himself a blessing similar to what someone else has, without wishing for its disappearance. This level is pardoned in worldly terms and is religiously encouraged.

The first and second stages are absolutely reprehensible. The third stage contains both reprehensible and non-reprehensible aspects, and the fourth is Ghibtah.