How can a Muslim woman please her Lord and have her prayers answered, especially if she suffers from unintentionally falling into sins and from intrusive thoughts during prayer?

Whenever you sin, repent sincerely, with truthfulness, and a firm resolve to abandon the sin, and regret it. For the door of repentance is open, and Allah accepts it no matter how often the sin is repeated. And the one who repents from a sin is like one who has no sin. Adhere to supplication and do not despair, for it is not a condition that the desired outcome be achieved immediately. The benefit may lie in the delay, or in the reward being stored for the Hereafter. Therefore, entrust your affairs to Allah while taking the necessary means, and be diligent in seeking times of answered supplication and the etiquette of du'a. As for intrusive thoughts (waswas), their remedy is to disregard them, ignore them, and not pay attention to them. They will not harm you as long as you dislike them.