How so? She was out before Maastricht was signed. Germany wasn't even unified when she was around.

She lost her job because frankly she presided over 3 terms in which she completely lost her mind part-way through the second and into the third and had to be removed by her own party who saw the writing on the wall. We don't have a term limit in the UK (and perhaps we should), but I still remember the "We have become a grandmother" moment which may sound trivial but was a shining example of how mental she became towards the end.

I would say if anything the thing leading to her being stabbed in the back was the way the poll tax was handled. The conservatives knew that if pushed through it gave Labour a credible chance of re-election, and that her reactions to it rendered her completely uncontrollable. They needed someone that senior tories could manage, which is why we had John Major (who for my money was one of the best PM's we had in a long time).