One of my main characters is bi, but she won't come out or get in a relationship until the second book. I want to foreshadow it in book one, so it doesn't come out of nowhere but I'm worried it'll seem like baiting. Help?

There are several different options for you. Here are a few examples of what you could do to avoid queerbaiting: 1, have your bi character talk to herself with monolog about her sexual orientation; for example, she sits on her bed and says, "Now isn't a good time to come out. I should wait a little longer." 2, you could have your character point make a joke about her sexuality with dialogue between her family/friends, but never explicitly state that she's bisexual. 3, she could be shown researching bisexuality on her computer. There are many different approaches you could take without queerbaiting. See if you can come up with an idea that fits the story.