Join Date: Dec 2013
Location: Boston, MA, USA
Programs: UA 1K, DL Gold, IHG Diamond AMB, MR Gold, HH Diamond, Hyatt Globalist, National EE
Posts: 1,087
It shouldn't be an issue. I have family members check-in all the time before I get there, and sometimes I book rewards nights for them.
As long as their name is on the reservation as an additional guest, you should be fine. If you want to play it safe, shoot over a quick email to the hotel explaining that a family member will be arriving first.