The reason I don't feel like they have a nanny - or anyone else helping them regularly - is because why would Jenn allow someone to come into their private home? And know where they live...and know what's being said behind closed doors... and see private areas (i.e. bedrooms, bathrooms, paperwork lying around, etc.) and be with her and / or them always?
Her personality is one that doesn't bode well with "competition."
They also barely have friends and no family ever is mentioned anymore (outside of lies about not seeing them).
So why would they have a separate person - especially right now during the pandemic and how they are so nutty with regard to any and all contact they have with people (i.e. masks in their own backyard) - come / go just to take care of Jackson?
I know I saw the DD gal helping at EPCOT that one day when she was holding Jackson while Jenn was stuffing her face - but that was at EPCOT, and I know the VIP Tour Guide was pushing Jackson another time at AK - but again, that was at Disney.
But I just find it entirely hard to believe these two would bring someone in regularly to take care of Jackson. (even if they ARE idiots)
Jenn is just NOT the type to have anyone else touching or caring for her child (repeatedly), any competition for the baby's attention, any competition in the mothering "department, etc. I just don't buy it.