Lae'zel urgently wants to reach the Creche before she turns into a mind flayer; why would she be perfectly content with the party taking a long rest every hour?
Problem with this theory is that you dont "rest every hour" ... ever. :-/
Every time you Long Rest the day is ended ...
Since time in game is static rightnow no matter how much real time you spend between Long Rests that is allways and every time 24h from game perspective.
On the other hand she can just complain that the searching for creche in your company is just taking too long ... and both idea and story integrity remain intact.