>> Can I combine the two?

Yes! just plant the rooted cuttings together with the mommy plant. You may need to unpot the mommy first if there is not enough space to dig around to plant the babies, or if you think you'll damage the mommy-roots too much or won't be able to give the baby roots enough space or to position them properly (outward and down as much as possible). Unless the mommy pot is almost empty, I'd bare-root her and plant the two generations together - this seems easier to me than doing it with the mommy intact.

For future reference, it could have been even simpler than that. Pothos is relatively to very easy to propagate, depending on the variety. I've tried with satin pothos and with marble queen, and the former was more cooperative than the latter, and it also grows faster.

With satin pothos, I just slice off a several-node-long tip of the vine, or several segments of the same or different vines, remove one or two lowest leaves, poke a hole in the mix in the same pot with a chopstick and stick the de-leafed nodes into the hole, with rooting hormone or without - they all took in my experience, and pack the mix lightly around the cutting, then water the whole thing in. The cuttings do not even skip a beat before rooting - very little wilting, and even that was temporary.

This did not work for me with marble queen - I think because it grows and roots much slower. The rooted plant requires more water, but the cuttings do not need nearly as much, so they rot instead of rooting. Pretty simple solution is to stick the cuttings into a separate pot, generally with perlite for the medium because it both retains some water and also drains really fast - then water the cuttings very sparingly, unlike the parent plant. You might want to cover the cuttings pot with a clear plastic bag to create a humidity dome, as they can only rely on leaves to take in water until they root. Open the bag periodically to air the space out, Once you see new growth on the cuttings, it means they have rooted. Can gradually remove the bag and gradually water more - then you can join the two generations together in the same pot if you want.

It's highly unlikely you will seriously mess this up. Pothos is a very forgiving plant. Good luck and tell us how it goes.

I do this a lot, with Pothos and many other vine/creeper type plants, if I want a full, bushy pot instead of long growth like you described. If necessary, I use a finger or a screwdriver and gouge a hole where there seems like room, and stick the new piece in. Often they'll just go in without preparing a hole first. If the parent plant has established roots throughout the pot, they will use the water around the cutting more quickly than a cutting by itself, IME.

This is the mama plant, Epipremnum, NOID cultivar that's been around the family for decades. When it went outside this spring, I cut off everything past the rim and stuck it back in the pot.

Looking straight down at the pot, barely any view to the soil.

Under the leaves, the tangle of stems. Every time one is cut, it needs to grow a new tip. I just took cuttings a week ago and some new tips are starting to poke out.

I'd rather have Pothos going up instead of dangling, so have added a few pieces to this pot with Monstera, satin Pothos, a couple small rhizomatous Begonias. It's been almost 2 months, so must have taken root to still look so normal. It may discard that one leaf with the spot.

"Regular" Pothos is Epipremnum. Satin Pothos is Scindapsus.