LOL
Pelosi, Schiff and company have been trying to turn the nothing-burger of Trump's phone call with Zelensky into an impeachable offense, but even if the Senate were to convict Trump on such a flimsy pretext, how would the Democrats get Pence removed? And he would be able to pick a new VP (although it would have to be someone who could pick up some Democrat votes in the House).
If both Trump and Pence were somehow removed, Pelosi would be Acting President. I don't know if there is anything in the law about succession to the Presidency which says that she would actually be President.