Update: Ya'll, because this portion of my tax return with Turbo Tax was so opaque and confusing to a lay person like me, and the dozens of answers I read by the "experts" in these community Q&As only offered unhelpful, simplistic variations of "the IRS only requires that you enter values equaling 100%", I gave up and went to an in-person tax prep service. I was so relieved to snag an appointment with them in the final weekend, and I'm very glad it's over and done. Long story short, I was not allowed to leave SLCSP blank so I ended up putting 100 for me and 0 for my daughter and paying the $1500. But at least I got answers and help from a friendly, efficient, real person sitting in front of me, instead of stressing at home in front of my computer.
