I was sewing by the time I was 10 years old. Back then, we didn't have embroidery machines or any fancy stitches. By the time the zigzag and cam machines came out, I was 20. I immediately bought one. Looking back, if I had the embroidery machine, with all the knowledge of computers that youngsters have these days, I would probably have been digitizing or own my own 10 needle embroidery business by now.
Having said all that, I love my Brother Runway machine I purchased at WalMart. It is lightweight, doesn't move around when you sew on it, and the decorative stitches are wonderful. It is a great starter machine. She will learn a lot on it and use it for many years. I, also, have my big Brother, Innovis D 4000. It is a wonderful embroidery machine and sews a great quarter inch seam. I don't try to pack the big one around. It just weighs too much.
As to the top loading bobbin, my Singer Golden Touch & Sew I bought about 1970, had one of the first one of those. I bought one and fell totally in love with that front loading bobbin. I have never regretted it for one instant even though I have had some minor problems with thread getting hung down in it a few times. It is so much more simpler when you can see what you are doing. I just pulled out the bobbin, the bobbin holder and used my tweezers to get everything out. Piece of cake to fix it.
Congrats to you for getting this young girl going in sewing. This is one gift she will remember all her life. Of course, you know she will want to go through your stash as soon as she has something to sew with. What a great time you two will have!