She is rising. I think she is fine without it. But I'd maybe test again if you're not giving her a snack.
It's hard to tell how food influences Billo because it isn't recorded in her spreadsheet.
Usually with TR, MC/HC is reserved for a drop below 50. Or sometimes, early on in the cycle if kitty drops into the lower 50s. There may be other times to use it. But this is what I do.
When Billo dropped to 55 @+6, I personally would have given her a bit of LC to see if she would surf and not drop lower. I would've then retested in 30 minutes, and if she was rising, I would not feed her any more food and test again in an hour. Because it is later in the cycle and I see Billo sometimes nadirs around +6, I would not feed MC or HC unless she went below 40. Maybe others would have done something different.