Smaug,
MEK may not be available in your area, acetone is a good second choice.
Also, after washing with MEK or Acetone, let the doll sit for at least an hour before applying the Silpoxy. The solvents will reduce the adhesion of the glue.
You may want to do the repair in sections, bending the leg to bring the two sides of the silicone together.
After applying the Silpoxy and bringing the two sides together, sit and watch the repair area. Some Silpoxy will leak out. This can be removed by gently wiping it away with an acetone soaked towel. Paper towels are fine for this.
Most importantly, GO SLOW! Better to take 2 or 3 days getting a repair that looks good.
She is a beautiful doll, with care you can repair her to close to perfection.
Mahtek & his Ladies