Good exercise routine?

[miku Kagamine]

I walk 30 minutes on my treadmill and do about 15 - 20 minutes of pilates, push ups, crunches, sit ups, etc etc

I have a healthy diet too
And I drink about 3 liters of water a day

Thanks
my goal is to lose 20 lbs (140 lbs, 5'2")

and get a little bit muscle tone
and to gain overall fitness