If the Romulans were moving in closer wouldn't the "appearance" of the emotions of several hundred to maybe a 1000 individuals pop up on her senses and draw her attention like the sound of popping balloon draws our attention?
And didn't she say that there were people in the Stardrive section in Disaster
? If so that would indicate that she could get a direction, not as precise as in Nemesis
, but a phaser sweep or torpedo in that area should light them up...and do some damage, even if minimal, in the process.
One last thing emotions are different from thoughts. A species might be able, through training - like the Cardassians - resist telepaths. But even in DS9 when the Vulcan was trying to mind meld with Dukat, I'd bet Deanna would sense the fun and joy he was experiencing showing off how well his mind is trained. A cloaked ship that may be coming into battle should put off some emotions like fear, or joy in knowing they had the Enterprise is theirs if they wanted her. The Ferengie and Breen (it was the Breen that Betazoids couldn't read?) would always be able to sneak up on Deanna because they simply do not register on her senses.