My kids are 4 years apart.
My younger one, my son, since birth and for the first 5 years, he was a REGULAR napper. On his own.
For the first year of his life, he'd nap 3 times a day.
My daughter was already in Preschool and then Elementary.
So, BEFORE I picked up my daughter, he'd have a nap. Then, AFTER I picked up my daughter from school, he'd nap again as soon as we got home.
My son would routinely nap, for 2 hours.
And he did this, all the way up to about Kindergarten. At which point, he'd nap, after school.
And his naps, were done around my daughter's school start and end times. And it was fine.
My son, regularly napped, at certain times. Which was also according to the school schedule my daughter had per drop off and pick up.
AND my son was not a portable napper. Meaning, he could NOT nap, in a car or in a stroller. He only napped, at home, in his crib.
And it was fine.
I put him down for naps, at regular "scheduled" times, which was per my daughter's school times for drop off and pick up.
Per your baby's afternoon nap, why does it have to be a "motion" nap????
Just put her in the crib.
At 6 months old, a baby typically makes noise/self soothes/and may rustle a bit or babble/make noises... but this does not mean, you have to pick up the baby and rock her/carry her/put her in swing. Just leave her be, in the crib, and let her go back to sleep.
My son was like that from 6 months old... BUT it was his "rhythm" at that age. ie: he'd nap, sorta rustle and make noises in his crib, but he was FINE.... it was not him WAKING waking. It was just, his sleep rhythm. And after doing that, he WOULD go back to sleep on his own. It was not him waking.. and being done with nap, it was just his sleep rhythm. At that age. Because their REM sleep stages are changing. They are 6 months old now. Not 1 month old.
Sleep rhythms vary at that age. And just because they seem... to "wake" intermittently, it does not mean, they are awake awake or need, to be picked up and rocked/carried, etc. I went according to my son's noises and cues. And he'd just sorta 'wake' after falling asleep during his nap, but then, go back to sleep. On his own. If I let him be. But IF he saw me.... he'd then, WAKE wake. And then it was me, disrupting his, nap.