The time varies amongst different females. If your not that experienced with palpating they may have to be pretty large to feel, with experience and knowing what your feeling for you can start to feel them at smaller sizes. It can take up to 6 months for females follicles to grow large enough for them to ovulate. This isnt something that you can do in a couple months, its a year long process. For instance, I started pairing in september and I was only able to start feeling fairly large follicles at the end of february, but I'm not that good at palpating. Get on youtube and look up palpating ball pythons, it might help to answer your questions.