Yes.
And the thing is, to be elected Speaker, traditionally you need a majority of at least 218 votes.
Suppose we have 230 Democrats in the House. If just 13 of them withhold support for Pelosi, they can, at a minimum, extract concessions or embarrass her by denying her a first-ballot victory.
In other words, what she’s trying to lock down right now is more than just a simple majority of Democratic votes.
Trump, of course, has said he’ll get her some Republican votes if she needs them. You can evaluate his motivation separately from his ability to deliver.