The quantum properties of fluorescent nanodiamonds offer great promise for fabricating quantum-enabled devices for physical applications. However, the nanodiamonds need to be suitably combined with a substrate to exploit their properties. Here, we show that ultrathin and flexible glass (thickness 30 microns) can be functionalized by nanodiamonds and nano-shaped using intense femtosecond pulses to design cantilever-based nanomechanical hybrid quantum sensors. Thus fabricated ultrathin glass cantilevers show stable optical, electronic, and magnetic properties of nitrogen-vacancy centers including well-defined fluorescence with zero-phonon lines and optically detected magnetic resonance (ODMR) near 2.87 GHz. We demonstrate several sensing applications of the ultrathin glass cantilever by measuring acoustic pulses, external magnetic field, or CW laser-induced heating by measuring Zeeman splitting and thermal shifting of ODMR lines. This work demonstrates the suitability of the femtosecond-processed ultrathin glass as a new versatile substrate for multifunctional quantum devices.