(SOLVED) Vintage Harlequin (80s?) h blackmailed into marrying H to save younger brother. Younger sis

The last chapter or so of the book has the h getting all dressed up for a dinner party where the H ignores her and there's a huge fight when they get home. I think she bundled up the dress (a gown and she got her hair done also, I think) and throws it in the trash after the quarrel.

The h's siblings overhear the quarrel and are indignant on her behalf. There's a showdown the next morning at the breakfast table.

I think the book is based in the US (unusual for Mills and Boon Harlequins of the 80s) but I may be wrong.

When all is well, H admits that he saw h's photo on the brother's desk and was fascinated by her. I want to say she's a redhead, but can't be sure.

I have this book in my collection and have read it multiple times, but don't recall the name or the author or any other useful details.

Any help will be appreciated.

Thanks in advance

EDIT: Found it in my collection. Jeanne Allan's One Reckless Moment