Any guidance would be appreciated.

My fiancé, who is 33, has lost interest in being intimate with me, and even in sharing kisses. I've noticed she spends an increasing amount of time on her phone, which has made me feel uneasy. This evening, I walked into the bathroom while she was taking a bath, and she quickly turned off what I suspect was a conversation on her phone. I sensed something was off, and after pressing her with questions, she admitted she had been watching lesbian porn to see if it aroused her. She’s also been engaging with people online and asking questions about how to determine if someone is a lesbian. I can't shake the feeling that there's more going on. She's been secretive about her phone, and when I requested to see some pictures, she hastily deleted them, claiming they were just selfies of her face, which I find hard to believe. Our relationship used to be strong, but ever since the birth of our daughter, who is now three, there have been noticeable changes in her behavior. For instance, she's recently started getting waxing, staying late at work, and even went for an unexpected walk to the store one night. She has agreed to start counseling, but I'm not sure what steps to take next. Any advice would be greatly appreciated.