HaBO: Regency Series Where Brothers Marry Sisters (Not Theirs!)

This HaBO is from Kassi, who is looking for a Regency romance series:

I’m having a hard time finding a Regency series I read in the 2010-2011 time frame. I’m not sure when the books were written, but recall that there were 4-5 books in the series. I only really remember 2 of 5ish pairs of characters well.

The series started off with a heroine in family trouble- money problems, a disgraced family name (father/step father/uncle was possibly some sort of traitor?), lots of siblings to care for, getting blackmailed into something, etc…

I don’t remember much from that story, but in the 2nd or 3rd, the brother of the hero from book 1 falls for the sister of the heroine from book 1. The heroine of book 2/3 is of the wallflower variety and has a vision or eye affliction (or maybe it’s headaches) and wears green tinted lenses to help her see. The hero is a grumpy, self-conscious, war vet, recent amputee (leg from the knee down) and finds the heroine’s green specs totally attractive.

The other pairing I remember well from the series was from the last book and I believe the heroine was the youngest half sister or step sister who was “ruined” and dumped following a tryst so she flees to Paris to study as an artist under an older, well respected but cranky, female mentor. The hero of the story is introduced as the artist’s “muse” and ends up posing for paintings in provocative positions with the heroine on behest of the artist. The hero is of mixed heritage and has quite the back story (he’s a brilliant ex-scientist widower who lost his wife in your classic experiment-gone-wrong-cottage-explosion and is tortured with guilt over his wife’s death). The hero is unfriendly to the heroine at first, but both succumb to their mutual attraction to each other. I think the main conflict in the story is when hero skips out on the heroine because he’s overwhelmed with his feelings, feels the need to start amassing wealth (apparently modeling wasn’t the lucrative career is it on Instagram today), and confront the loss of his first wife. He winds up working for the hero of book 1 and uses his uncommon smarts to maximize profits for their maritime trade business. Meanwhile the heartbroken heroine hones her painting skills and puts on her first show. A mysterious patron buys up all her paintings immediately and turns out to be the hero returned to claim his love. The family is totes cool with pairing and the heroine is reunited with her family.

Clearly, I remember quite a bit of the last book, but I just. can’t. recall names, titles, or the author. Ugh. It’s become the piece of popcorn stuck between my teeth. I remember enjoying the series a decade ago and I would love to revisit the stories now to see how well they’ve held up.

TL;DR;
-5ish book series
-brothers marrying sisters (not related to themselves)
-book 2 or 3 pairing: Wallflower tinted spec’ed heroine x grumpy amputee hero
-book 5 pairing: Artist in residence heroine x POC ex-scientist model hero

Sometimes you just know a HaBO is going to get solved.