My ladyfriend has a sewing machine as well and we both plan to learn how to use it this summer for alterations at minimum, and I'm actually hoping I can learn to make a shirt. Plenty of old ones laying around that I can reverse engineer I wonder whether the cost/availability of fabric makes that pursuit worthwhile, though.
go for it man. you are lucky having a coach, be nice to her. it just takes patience and lots of time.
be prepared to rip stitches and resew again and again, like i said patience.
^^this... On the first few pants/shirts I've done I probably ripped 3x as many stitches as I kept. So be careful. I have a hole in a pair of pants and in a shirt where I was trying to run the ripper down the length of the stitch and it got caught in the fabric giving me a hole.