What if the princip of Leiningen live more and not die so early, making the mother of the queen Victoria remains marriage with him and the queen not born, how the not born of the mother of Europe influence the Europe?
It's essentially opening the door to a butterfly-sanctuary IMO. Since Princess Charlotte might marry differently or even survive her OTL death; George IV or the duke of York may remarry if Charlotte still dies; the duke of Clarence may marry differently (to either his cousin, Sophia of Gloucester or Amalie of Baden, both of whom were proposed); or one of William IV's kids may survive; the duke of Kent might be a little smarter and not wait around in wet boots for a packet of newspapers from Hannover etc etc etc. On the surface, it wouldn't be a
massive thing, but it's a case of even one raindrop raises the sea. Even
if everything remains as OTL, Kent will marry differently (where I can't say. Since Amalie of Baden was being proposed for him at one point, but he rejected her because he didn't want the emperor [Franz II's] cast offs (Franz had displayed an interest in marrying her at one point), and because of her age). And AFAIK, Victoria's half-sister wasn't a carrier of haemophilia, so even in the (very unlikely) event that Viktoria of Coburg still produces a daughter who
does carry the haemophilia gene, chances that that niggly little bugger (the gene) will wind up in the Spanish/Russian ruling houses like OTL is
pretty small.