Okay, first off it makes a big deal if she was 8 years 3 months or 8 years 4 months, so assuming she was <8:4, yes, her new Similarities score would be 19. Thanks for sharing by the way, as given that it lands in the "higher" half of 19, I'm pretty sure my own son's 18 would have gone up as well (no raw scores,

).
The VCI would go up to 150, from this one point jump.
However, it appears there are two totals for a full scale of 144. You'll have to go back and add all 10 subtest totals (the 1-19 numbers) to figure that out. Don't add the optional tests if you have them (Word Reasoning, Information, Picture Completion, Arithmetic and Cancellation).
If your total is 158, the full scale is 144 (might be original total)
If your total is 159 (with possibly your new point), the full scale is still 144.
However, if your total is now 160 (if it was 159 originally), the new full scale is 145. What a way to land in the golden zone if that's the case, LOL!