Too much or not enough?

This is my first post so I apologize if this is in the wrong place.

I am 5'3 , 10 stone.

I walk around 1 hour 20 minutes everyday.

I am looking to start jogging 20 minutes as well every night

I also am doing light weight lifting.

Is this enough excersize to see results? Hopefully 2 stone in around 5 months (ready for prom!)

I have a very healthy diet :)