They mean the same. There is the difference in the verbal aspect. Pronalaziti is imperfective and is good choice for your first sentence: Kad god zagubim/izgubim jaknu, ona je pronalazi, although the verb nalaziti can be used as well. This verb can be also used in past tense Kad god sam gubio jaknu, ona je pronalazila. Whenever I lost my jacket she found it. The imperfective is used in the past tense for actions that took some time, for repeated habitual actions. For another sentence te verb naci or pronaci,the perfective form is fine because it happened once and the action is complete/finished. Nasao sam or pronasao sam jaknu na zadnjem sedistu svog auta.

PRONALAZITI is an imperfektive verb: The duration of its action is not limited. (...I keep finding new facts ...) PRONAĆI is a perfective verb: The the duration of its action is limited,. The action was completed. (...you found some more facts ...)