The pants are ready, I´m pleased with the outcome, they are a bit long, but I did that on purpose so that they will be perfect next winter. The recipient of the pants was happy.
I have decided to sew a heart on the knees, the method is a success and the instructions are very simple (just followed the picture) however the heart I sewed on was way to small, the proportions are a bit off, need to make a more appropriate size before I can declare this project finished
I used a drops pattern, but made some modifications, so that they fitted my slim baby and the yarn I used. Will be publishing the modifications I made.