It can take up to 30 hours or more for them to complete the process, but she sounds o.k. That spit sounds a bit odd though. Position her so her beak is pointing down and see what she does?
I can't tell from the pics... Look at the article I linked for you above, there are pics showing what the membrane should look like. You can use that for comparison.
You got some good advice here. In my experience malpositioned chicks can take a bit longer before they are ready to hatch, because they skipped the internal pip (into the air cell) stage, therefor this stage, which can take up to 7 hours, needs to be included in the normal time it takes them to...