Simply talk/sing to her and tap your tummy lightly, or try drinking something cold or have something sweet and see if baby reacts to it. Some days they are less active than usual but if it still worries you, make an appointment with your Gynae for a peace of mind :)
If you are worry please check with your gynae....
Better call up gyne
As long as you are very sure that baby is not as active as before. Best is faster call your medical provider. They shld be able to guide you what to do next.
marzx.h