S.J.
I'm so sorry if this offends you, but I laughed at the last line of this. You seem like you're trying to hard to convince yourself that you are so lucky to have her. I'm sure you mean that to a certain degree, just maybe if you two could communicate better.
Your mom is visiting you, which means she loves you. She is probably just as uncomfortable as you are, but is afraid if she stops visiting you, she is going to be making the choice to let her baby go from her life. She does it because she's afraid of not being a part of your lives, but it seems that you two probably just don't know how to communicate. You seek her approval, and that means something. I'm not sure what it means, but I know it means that you care.
Without knowing anything else about your relationship or how it was with her growing up, or when it became so awkward, it's hard to give you advice. I think the best advice is that she probably isn't judging you nearly as harshly as you think she is. She's probably very proud of you, and just doesn't know really how to say it. I'm sure her hope is that one day you two can actually enjoy each others visits...so maybe relaxing is actually the best way to do that. Don't stress so much, just try to have fun keeping in mind that thats's probably what your mom wants too.
They say at a certain age your mother is supposed to become your best friend. There's a reason they say that. She's a person too, who was probably just as nervous around her mother as you are around her. Just try to talk to her. Getting a glass... or 5 ...of wine usually helps me in these situations.
Best of luck and warmest wishes to you!!! :)
Oh, maybe just try asking her about... HER... and how motherhood was for her. It might be uncomfortable, but it's a start. Those are never comfortable, but you never know where it may lead. She's not going to live forever, you should try.