Didn't get as much height on day 13, but I adjusted it's placement in the house and started covering it with an extra towel to keep it dark and warm. A couple of my bread-making friends suggested I should keep it out of direct sunlight. Another suggestion that I found helpful was to have a lid or plate on top of your jar, not just a tea towel. I put a heavier plate on my jar on day 8 that may have helped, but with unpredictable house temperatures it's hard to know for sure.
Image Source: POPSUGAR Photography / Tara Block