If you want to make a universal-metric-prop for yourselve:

1. Switch units to centimeters! (Edit --> General Preferences --> Interface --> Units --> centimeters)

2. Load the "box" primitive.

3. Scale it up to 381.5 %

4. Export it as a Wavefront OBJ (FILE --> Export --> Wavefront OBJ...)

5. Save it to your desktop as obj file.

6. Re-Import that obj file again (FILE --> Import --> Wavefront OBJ...)

7. Now it gets a bit tricky: Open the Joint Editor. (Window --> Joint Editor) Set the CENTER values to ZERO. (See pic)

8. Save it as a new prop to your library.

Now you can directly measure anything.

Here I loaded the original DAZ GIRL at her default scale. Scaled up the meter cube until it matched her height, and the yScale tells me immediately that she's 177cm tall.

In my opinion, that's too tall given her proportions, so I scaled her down to 85% and saved her back to the library. She now loads with a height of 150cm.