The timing she's looking for is the time that she has the 218 votes on the House floor needed to impeach the President. Presently she has at most 40, no more. If she had 218, the vote would have happened already. If Nadler's committee were to vote out Articles of Impeachment and she didn't hold a floor vote on them due to lack of yes votes, she would loose her Speakership. If she did hold a vote she would loose so embarrassingly she would loose her Speakership when the Dems loose the House in 2020. There will be no impeachment of President Donald J. Trump.
As politely as possible I will say you are missing the point.
Based on what we think we know at the moment, Pelosi may realize she doesn't have a majority vote of the House for impeachment; however, she does not need that vote for the scheme I envision. Note my post says nothing about a vote.
The timing I refer to is a product of the limited number of days she can spend entertaining the MSM with House proceedings similar in the style of the Ballsy Ford episode. Nadler and his committee will open the door for her in that regard.
Her start date would be the first of the days necessary for witnesses, arguments and whatever else she can generate that would be reasonably relevant and capture the concern of the public. Her completion date would be as close as possible to any R primaries with a backup plan for the presidential election, if necessary.
We do agree on one thing, based on what we know today Trump will not be removed based on impeachment.