well, Tessy is "just a normal Lux girl" without a posh education, she knows how "normal" people live and what they do, sth you do not learn at the most expensive boarding school in Europe or in a Belgian castle. Yes, she might have grabbed her chance when Louis visited the troops when she was a soldier but she doesn't seem to be a gold digger to me. Not so sure about Linus and Claire, they both seemed to be thrilled with the princess status and both have this superior attitude. MT still seems to remember how badly she was treated by her own MIL and that might be the reason why she is nice to all her DIL but I wonder if she secretly regretts that Louis and Tessy are not in line any longer. Tessy and the boys seem to have a great relationship with MT, the boys seem to have a very close contact with their grandparents, so I would say that Tessy is well accepted by the family.
Excellent point, Trier

I give Tessy a lot of credit. She may have appeared as a gold-digger when she first appeared on the scene, but honestly, I just think she and Louis were dumb kids who didn't do anything to prevent a pregnancy.

Since that time, she's never spoken to the press (and she really could have in the early days-especially since she married him and wasn't given a title at that time), she's proven herself to be a good mother who seems to genuinely love Louis and her sons. She's always shown up to events with a smile on her face, and has usually been appropriately groomed and dressed. She doesn't appear to be trying to take the spotlight away from her mother-in-law or other family members. She doesn't associate herself with things/organizations that could be considered radical and fundamentalist (a la Claire). She seems to be happy to be at events where she gets to meet the people of Lux

It's a shame that she's not the HGD. She may not have had the elite education and training that Stephanie has, but she seems far more suited to the job. She's the only one who appears to be able to follow in MT's shoes.
Even Louis, who also doesn't seem like the sharpest knife in the drawer, seems to have more poise and warmth than his brother, the heir. The contrast is amazing, IMO.