2000 CRV 76,000 miles - never had valves adjusted

This car was purchased new and is owned by the proverbial "little old lady"  Although
she has done regular maintenance she has never had the valve's adjusted.  We're going
to have a compression test done but can anyone give us an idea of the probability of
valve issues?  The engine does not have any rattle or loss of power.  Idle seems to be
fine.  

It's a great deal but I don't want to find out I have to replace valves.

Thank you!