Well, yeah. If you want to complete a whole year’s worth of work. If the pace is too fast, can your D just take Latin 2A, i.e., the first semester’s worth? Or perhaps pick it up a a community college with an 8 week schedule?
17+15 = 32 days. Our HS summer calendar is 30 academic days. But our HS offers only a few full-year courses during summer school, and most of those are for remediation (D’s and F’s looking to pass).