Something was bugging me about the way the Tamara events were coded, so I looked them over again. I think the answer is actually yes (not 100% certain), but it doesn't make a lot of sense.
IF I'm right, you would still get to do everything with Tamara, and get Sis/Fred/Danni, but Tamara would act like a cold bitch when you tutor her.
- This is almost certainly a bug/oversight, so you might want to consider if you actually want to do this. It might hose your save in later versions.
- I would suggest not advancing Derek's investigation at all during this. This loophole doesn't technically close until the club has its first meeting, but there is no reason to chance it.
- Tutor Tamara and be flirty until she asks to hang out after school. This sets her as available to meet on Monday. Like her suspicion, this variable can only go up. It is never unset and her suspicion is never checked for it. Skip actually meeting up with her for now.
- Complete Tamara's investigation line until Freddy and Sis hookup. This will set Tamara's suspicion to 1. This permanently blocks her study sessions, so it will make it a little more difficult to raise her love and lust.
- Take Tamara up on her offer to meet after school. She should join up the next morning, if you haven't monkeyed things up.
- Have you cake and eat it too.
I'm not looking into it, but I'm now curious as to whether this might allow the club to technically have more than four members. Once Tamara is suspicious, she's not suppose to be able to join. So you might be able to get both the substitute member and her. I imagine the events are coded to include the champions if they've joined, so I doubt there will ever be five people standing around, but the count technically would be.