Sudden bad behavior with family dog

Recently our dog has been having very puppy like tendencies that we haven’t had issues with in years. She’s going to be 4 in December and all of a sudden we can’t turn our back on her without her getting into something. We used to occasionally have a trash issue but now she will dig in the trash right in front of us! If I go upstairs quick, she will eat food off the counter. Which I’ve never had any issues with before, last week I had to make 3 different batches of cupcakes because she kept eating them! No matter where I put them, she got into them 🤦🏻‍♀️ She’s a Great Dane and so she’s tall as shit too. She’s been chewing up our babies toys and everything. My daughter is almost 9 months so the baby isn’t a new factor. Is she going through a midlife crisis or what 🙄😅