To make her arms longer you use the scale dials.

I just selected the shoulder and scaled the length to 108 and the forearm to 109 which puts the fingertips right below the hipline. The elbows at the bottom odf the ribcage.

This is using my own arms as an example to get an idea of how long they should  be.

If you bend your arm and check the length of the forearm against the upper arm, you will see they are the same, or almost the same length. Most 3d models have a shorter upper arm for some reason.

 

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     BluEcho...Faery_Light...Faery_Souls.