I don't like to rate bars that just open.
1. They normally don't know what they are doing
2. They ask for leeway because they just started
Your mother's house. Having a lazer focus on who they are and what they are, more importantly who they seek to serve and how they want to do it. Gives me the confidence in saying that they will deliver on their promise.
The promise being, it will feel like you are going to your friend's house (which is their mom's house) to drink.
It remains to be said if they will deliver their promise, in a unique way. So I will reserve the ful rating for until they are more mature.