A system for controlling a flow of fluid includes a flow control device having a fluid channel configured to transport a fluid between a subterranean region and a borehole conduit, a resonant sensing assembly including a resonator body disposed in fluid communication with the fluid channel, and a controller configured to cause the resonator body to vibrate according to an expected resonance frequency of the resonator body. The system also includes a processing device configured to acquire a measurement signal generated by the resonator body, estimate a property of the fluid based on the measurement signal, and control a flow of the fluid through the flow control device based on the property of the fluid.