Hi there and congrats!
Here's my 2c :)
Tessa Claire - I love this, and think it goes very well with Laura Audrey
Tessa Lauren - Nice, but Lauren is very close to Laura, esp with the different pronounciations in different areas. I know it's in the MN spot, but I'd personally prefer a name that's very different from her sister's name.
Tessa Madelyn - I think Madelyn, while beautiful, is fairly popular at the moment. Not sure it's my fav with Tessa.
Tessa Vivian - Also nice, and I like the feel of Vivian with Tessa. Feels similar to Audrey IMO.
So...I think my vote goes to Tessa Claire followed by Tessa Vivian :)
Good luck!
Elaine :)