I just finished Shooting Victoria: Madness, Mayhem, and the Rebirth of the British Monarchy
recommended. The assassination attempts are an inherently interesting topic, and Paul Thomas Murphy makes a great case for their importance. The British loved Victoria for continuing to put herself at risk of going among them despite repeated shooting attempts, and she returned their love by allowing democratic governance even when sorely tempted to override it.
Not mentioned in most reviews: This is a wonderfully realistic portrait of a successful marriage. Can marriage recover when the husband accuses the wife of killing the children*, and the wife says they never should have married? In this case, definitely, yes.
I'll warn you, though, it is not a feminist book. Victoria starts out determined to make all decisions of state independently. Then she marries a liberal German who turns out to be a genius at British politics, and gradually realizes he's worth listening to. If Albert had lived longer, it would have been hard to keep him from being the hero of the story.
* By listening to the medical men of the day.