If you can let us know what Yuki is asking you to do (which pose) and what activity she is doing with you (which scene), we can investigate the controls to see if we can improve how it works on keyboard and mouse.
Also, here's a tip: Anytime you can't perform a gesture with the keyboard and mouse, you can use the Journal to select the 'pose' or 'response' you would like to give.
Thanks for reaching out!