Yep, what she said.
Little musician is great for any age. It can be as passive or interactive as you want it to be. My 7-month-old lights up when we watch it. My 5-year-old watches it at the piano and plays the chords during "chord recognition". Little Musician is great for overall music education- reading music, singing, history, and instrument recognition.
It's hard to say what age Soft Mozart is for, especially here. If I suggest 2-years-old, someone is going to prove me wrong, which is great! But playing the piano does require fine moter skills. My 2-year-old is benefiting from it but I don't know if I would have bought it for him. My 5-year-old is soaring with it. Soft Mozart is great for piano- reading music, playing two-hands together, playing the notes correctly, etc.
We really love both of them. Not knowing your budget, I would recommend getting Little Musician now and Soft Mozart when they are around 2. If you do get LMS, you could color-code the piano keys to match LMS and when your daughter can match them up with lessons on LMS you'll know she's ready for Soft Mozart. My 2-year-old loves playing the piano with both of these programs, but SM is better for piano, naturally, because that's what it was designed for.
Good luck!