Firstly, I would not recommend doing so by hand. But if it must be done this way, at least use a legit tattoo needle. This will make it go much more quickly, and the broadened tip with multiple points will help prevent the needle from stabbing too deep like a regular sewing needle would. Tattoo needles are also designed to hold a decent amount of ink, whereas regular needles don't hold jack shit. Do not let her get high first! Some do this thinking dulling their senses is a good thing, but it only makes the pain worse and she'll focus on it more. Have a wet paper towel, many actually, to wipe it off every now and then so you can keep excess blood and ink away and clearly see the work you've done. Make sure she knows if she wants it done slightly differently, SPEAK UP. Tattoo artists love feedback during the actual process so that the end result is optimal customer satisfaction. If she says nothing and it ends up wrong, she's stuck with it for life, or until she can get a cover up.

Hope this helped, lemme know if you have any questions :)

Thank you soon much :)