Two languages means two URL trees, not a flag in the corner
A translation widget produces a site that ranks once, reads badly, and forgets which language the visitor chose.
Give Spanish its own pages at their own addresses, with their own titles and their own headings. Then the search engine has something distinct to index and the visitor has something a person clearly wrote.
Make the language choice sticky. If someone lands on a Spanish page, clicks through to fees, and finds themselves back in English, they will assume the Spanish part was a veneer over an English practice. Persist the choice across the session and carry it into the form.
Do not translate everything mechanically. Some pages need different emphasis in each language, and a few may only need to exist in one. That is a content decision, not a technical one.
If a meaningful share of your patients speak Haitian Creole, decide deliberately whether the site covers it. Half-covering a language is worse than not claiming it.