I absolutely understand how this feels dishonest for you, and I think I’d probably feel the same. But it’s important to remember that you’re there to do a job. So I’m inclined to ask how that’s going, and whether your lack of Jewish fluency is actually an issue for you, in your ability to carry out your duties. My guess is that it isn’t a problem, and that the only real issue is your internal dissonance over the secret.
Honestly, you might want to sit down and have a talk about this stuff with your boss. Not because you owe anyone an explanation, but because it sounds like you’re carrying around some anxiety, and that’s not good for you. My guess is you’ll find reassurance and an open door. If it wasn’t an inclusive environment, you’d know that by now.
Also, plenty of people with two Jewish parents weren’t “raised with much Judaism.” I’d separate the two issues in your head, if you can. It might be relevant to your professional life that you have some things to learn about Jewish practice/culture/etc, but I can’t imagine that your mom’s faith has any bearing on your performance.