You can get a nice Sony for under that price, or Phillips that plays divx ($63 at Amazon), or JVC, Kenwood, etc. and all will work well. These will all play DVD +/- R/RW and MP3 CDs.
You also can get Apex, HappyPuppy, etc. no-name brands for $40-50 but quality control is much worse so you may need to take back the first one or two until you get one without defects.
PS, Just find out whether she needs black or silver, see what's in stock at your favorite e-tailers, and buy.