Okay, sorry for the late reply, but I'm seeing a couple of aligned trends; in both the comments in this poll and the stories themselves.

Point one- her growth spurts seem to be triggered by stress (not unlike Caitlin Fairchild), her body is reacting to what hormonally equates to a sense of personal danger. Stress evolved as a survival response- it used to be triggered only under extreme duress, like when we were being chased by a lion; today we are bombarded by stressors, like when we catch someone lyin'.  The body can't tell the difference between anxiety as a result of peril and as a result of agitation.

Point two- there is a near consensus in the poll and the storyline to have her return to near her original size, though many would like her larger, and a few would prefer smaller. There is a range of interest in her size, and I believe an interest in her maintaining a range of size.

Point three- stress can be managed, that is to say she may be able to control her newfound growth and even learn to reverse it at will (with effort). I believe that channeled meditation, coupled with releasing any pent-up frustrations, could achieve this goal. As an added bonus, letting go of things that annoy her gives plenty of additional ammo for future storytelling. Not to mention, Maia could use Olga's power against her in arguments... as a lie detector when Olga tells her that nothing is wrong/whatever is happening is not bothering her.

Point four- though she is learning to better control her strength and agility, she is still concerned about accidentally hurting others... especially if she has another major growth spurt. To that end, I believe she would try to control her emotions, try to limit herself to levels she's already comfortable with. (meaning she would most often be at her normal size/power level).

Point five- even though she could use this to practice/fight at higher power levels, Olga would realize that the longer/more-often she does so the harder it will be to calm and release. Using the power risks being unable to revert back... at least for a while. Additionally, the power itself (aside from the anxiety it is causing, which is of course only escalating the situation) would likely be euphoric; Olga would also risk becoming emotionally, maybe even chemically, dependent- almost like a drug. (this to has plenty of story potential).



So, to join the bandwagon:
yes, she should go back to close to her normal size (though I wouldn't mind her being a bit bigger )
but, she should also change size from time to time... as appropriate for the story.
overall, she should be a bit stronger, faster, and more confident as a result of her journey... yet still struggle with controlling the changes.