You will need to drop your elbows if you dance with a substnatially shorter partner. You right arm will slope downwards from the elbow, but you left elbow will need to be down enough that you can match her right hand without excessively depressing your forearm (which would break the palm-to-palm connection or the wrist alignment).
The key to movement is to project the body weight forward into steps rather than trying to hold it back in balance while swining your leg forward. You need to get your body moving, to get your partner's body moving, to create space into which your free leg can accomplish a delayed swing. Similarly, don't bend your standing knee forward while keeping your body back - your body must advance over your standing knee to provide a "flat front" for your partner. Since these things take you off balance, you will have to carefully time the lowering so that it can procede directly through with the drive into the next step - once you have lowered, you can't delay or you will fall over.
That is of course a fundamental skill for any partnership, but it is extremely crticial in the case of a height mismatch.