I haven't tried out the turtle, but I have a 13 month old and a VTech smile that never gets used. By the way... I don't know how you feel about this, some people refuse to go this way but... I belong to a bunch of Yahoo groups that are local to my area. Some of the names are; georgia-recycle-4-babies-n-kids, Cheapcycle, Freecycle... anyway... They are sites where local people list items that they no longer want, sometimes free. The VTech Smile I got cost me $5, yes 5 dollars... It didn't come with a box, but has 2 extra games and, especially at such a young age, she would never know. As for the older girl 'noticing'... if you use the Santa Claus tradition, it could be a gift from him, just have it 'opened' and set up, or set up put then put a "tent" of wrapping paper over it! We have done that with our older daughter in the past and is great!
I would recommend toys like crawling tunnels with balls to roll or an indoor tent... most musical toys are great at that age as are blocks. Stacking blocks that can be knocked over are ALWAYS a big hit!