We receive s'char (reward) for fulfilling our halachic obligations.
Performing bedikot twice a day during the seven clean days is part of the taharah process required before mikveh immersion. Thus, a woman does receive s'char for performing bedikot twice daily and fulfilling her halachic requirements.
However, there are opinions that only require one bedikah per day, so a woman should not feel pressured to do what is beyond her limits. And according to all opinions, the number of bedikot can be reduced to one daily or even fewer in situations of need, depending on the individual circumstances. If you were instructed to perform only one bedikah daily because of scheduling difficulties, staining issues, difficulty with bedikot, feeling overwhelmed, etc., then you should follow that ruling and feel secure that you are keeping the halacha correctly, and receiving s'char for doing so.
May you always strive to keep growing, and keep improving your relationship with Hashem and fulfillment of mitzvot.
Please feel free to get back to us with any further questions.
B'Hatzlacha!