Get the turkey baster !!!
Have her stand on her head after sex for 1/2 half an hour.
Tell her she must hold them in her cupped hands every night while she hums the Battle Hyme of the Republic.
After a couple of nights of this she will be more than ready to let up ride the bike.
Better yet get a bottle of wine take her for a ride find yourself a field and let nature take its course and you will have little ones running all over the place in no time.