How can one get rid of memories of a previous marriage, and is recalling the intimate relationship in detail considered a sin? And is marrying someone of good religious commitment and character a solution to this problem?

There is no sin upon a woman for recalling memories of her private relationship with her husband, as long as no Sharia-prohibited act results from it. However, she should occupy her time with what benefits her in her religion and worldly life, and not surrender to these thoughts. If someone whose religiosity and character she approves of proposes to her, she should not hesitate to accept him, for marriage is a fortress against tribulations and a cause for tranquility.