Depends on why. Is it restitution for something? You had a huge rupture and this is an attempt to help heal that rupture? Or T made a huge mistake and missed a session and this is a make up? Sure, I'd accept a free session in that case. If your T knew that you hit a huge financial rough patch and this is temporary until you get back on your feet, also OK in my book.

Just because? Eh... I'm not so sure. And absolutely not if it made me felt like I would owe my T anything.