I've never got on with my sister-in-law. Her and DH are chalk and cheese, and are not close. She is money obsessed, snobbish and generally unpleasant. Although she and her husband both have well paid jobs and expensive hobbies (5 horses do not come cheap!), she is always crying the poor tale, and shamelessly guilt trips her parents into "lending" her money, she is not above threatening for them not to see the grandchildren if she doesn't get her own way. Her idea of "lending" isn't the same as mine, either - she never pays her loans back.
I've tolerated her for the sake of my parents in law and nieces, but that's it. She's never visited my house, not for want of being invited.
Myself and DH are older than her, and some years ago my father died. No condolences from SIL, no card, nor anything when I saw her face to face about a month later. She did, however, sidle up to me and say how lucky I was that I'm an only child as I'll inherit everything when my mum dies. I'm not often speechless but I was then - I was staggered by her inappropriateness and insensitivity.
Fast forward ten years and my mother died. As SIL so tactfully pointed out, I inherited the entire estate, apart from some amounts to some of my cousins. My mother had also very generously gifted money over the years to me and my two children. We were comfortably off before this, but this inheritance is quite a substantial amount - not millions, but house prices in the south east meant that the estate had increased dramatically.
Again, after this bereavement, no card from SIL, but I never expected one - I've barely exchanged more than a dozen sentences with her in ten years. However, two months ago I received an email from her asking for a loan of £15,000. (She got my email address from my mother-in-law - she's never had cause to email me in the past).
I actually laughed out loud when I read it. She's spun a real sob story about needing to set up a business and how it would be an investment. Big nope from me though! I was tempted to reply telling her to go f*%! herself, but instead just said that I am not in a position to lend money to people, and she should approach a bank. I was truly outraged though. How dare she? I want nothing to do with her at all now, not even for the sake of the rest of the family. Please tell me this is not unreasonable?