Hi. O'm not familiar with the 2 sites You mentioned (And have no need of their services), but as long as the webpages You create are made with Your own personal time & effort, & contain all the options the customer requests, You're providing a skillset at the rate for time You charge them.
The only DISCLOSURE You may want to add is that webpages created are limited to the asvailable features & functions offered at the time of build, & that hoesting services are provided by as third party & are maintained by that 3rd party regardng usage & access limitations, content hostable on the page(s), & / or administrative lockouts according to that company's rules & regulations ... IF those websites provide anything above & beyond being a simple online HTML creator utility.
And as long as You can save Your mainpages source files to modify on Your own equipment later (Most browsers have builtin WYSIWYG editing now anyway) without copyright infringement on their graphics or scripts, You are simply charging for a physical / intellectual serv ice, NOT acting as an authorized (in this case UNauthorixed) Distributor for the websites' services & / or contracts & copyrighted materials.