Getting a real machine to teach her on is best. Problems and frustration with the mini machines prevail. We restore machines and have not found any of the new minis to be a quality worth the price or headache. My daughter is 10 and will be 11 on Sunday. I have been working with her to learn as well as my 14 and 8 year old boys. A machine with a good smooth foot control and good lighting are probably the big keys. A jumpy peddle is both ruff on the nerves as well as dangerous for a beginning sewer. For my daughter my husband came up with the idea of plugging into a power strip which is at my finger tips so I can cut the power if needed like if she gets carried away. Each of the kids have been very responsable in listening when we sew- only work one on one with them and the others have to go away. First thing is to teach her the parts of the machine and to touch and operate them when you tell her Especially stop (lift your foot off the peddle) and raise the needle before pulling the fabric out of the machine. Second- there is so much for her to think about it is easier to just give her some fabric with stablizer to keep it nice and flat and let her just sew back and forth and around. teach her handling techniques and how to control the foot peddle speed. The no hands switch is actually harder to control when a quick shut off is needed or a corner turned- it is easy to shift the power from low to high and overshoot the off as well as panic while trying to reach for the switch. Go to Joanns and get a pair of snips- can find them by jewelry making supplies for under 2.00- same as thread snips just a lower price. Also pick up a fabric marker . We use water saluble for lights and a white pencil for darks. As she is learning it is much easier to line up that penicl/marker line with the needle then a seam line or other form. We keep a cheap magnet near the machine for pins which come out as we go- also helps to slow them down realizing they can't race. Each of the kids know this is fun yet very serious and they have to listen and follow every direction. So far projects have been bible covers, doll quilts, purses, bag from men's ties and so on. Stick to simplicity and very easy patterns if you use any at all. Butterick etc are not good for her or you as they are hard to follow and often more complicated then needed. Show her how to use the same pattern for many things. Wait for pattern sales and check thrift stores and rumage sales for them.
You'll both have fun- take your time- she may not be as thrilled over it as you for quite sometime. My husband bought our daughter a Pfaff ( lower end) because I have a good one and was not thrilled when she didn't just love to sew right off. I sewed young but didn't really appreciate it until into adulthood so I keep reassuring him the machine is still a good idea- especially to keep her from using mine. The boys have their own as well so there is no fighting or question about who did what to someone elses machine. We also use a travel iron instead of a full size for their little hands I have a wand iron but find the travel iron on a cotton dishcloth wrapped cutting board works great.