Dogwoods and shrubby willows come to mind. Alder if you want to add a tree or two. Which ones would occur naturally in your area?

Shrubby dogwoods are the most obvious plant. I used to have a pussy willow near my swamp which gave some height. However . . . .

Hedges, shrub borders - whatever you want to call them - are not really low/no maintenance plantings. They have to be weeded regularly or the poison ivy, shrub honeysuckle, multiflora rose, maple trees, etc. will take over. Then you'll be back to where you are with the exception of a few nicer plants in the middle. You'll also need a fence in there somewhere if you have river frontage and a toddler.

I'd put in the fence, and then a couple of small, shrubby trees. Most people don't need a total privacy screen, just something so they don't feel exposed. The trees will provide screening further up the bank.

BTW, your soil pH is probably neutral to alkaline. The Champlain valley, mid and upper Hudson valley, and the Mohawk valley all have very high pH soils for the East. I'm about 50 miles south of Albany, near the end of the Hudson finger of alkalinity.

I have planted silky dogwood on my property edging the river. It is doing well, very pretty. There is silky, red and yellow twig dogwood and grey dogwood. I also planted witch hazel, also doing well, there is a wetland species, Hamamelis vernalis that also smells good, hardy in your zone. https://plants.ces.ncsu.edu/plants/hamamelis-vernalis/

But Hamamelis virginiana will also do well. https://plants.ces.ncsu.edu/plants/hamamelis-virginiana/

Staghorn sumac also does well, and there are some more decorative cultivars out there now that I see in the nurseries . . . another plant that is thriving on my lot close to the river is a shrubby Serviceberry/Amelanchier. You could also maybe grow maple-leaved viburnum or highbush cranberry for some foliage variation. Not shrubs, but river birch looks great along a river, . . . obviously . . .

Some plants I see when canoeing along a river that I haven't mentioned are winterberry holly and meadowsweet which is a kind of spirea

https://www.wildflower.org/plants/result.php?id_plant=spal2

Thanks so much all! Will definitely look in to all of this. I didn’t even know there were shrubby dogwoods! And mad_gallica you’re probably right about the alkalinity. We’re about 35mi south of Albany and our well water has crazy high ph (9-10!!) Luckily (?) we don’t need a fence as there is an old wharf blocking direct access to the water, at least at low tide.

Pink mountain - we will definitely be adding several river birch as well, nearer the gazebo, but the shrubs will be for closer to the water. I considered witch hazel but doesn’t it grow really high? Do you prune yours? Or if not, about how high is it growing? I thought I’d read 20’ somewhere?

Floral UK it didn’t even occur to me to think about alder but now you’ve got me googling :)

Thanks again all!!