Anyone can worship Gaura Nitai, because they do not accept offenses. But if one does very nice worship for Them, They will help the devotee advance very quickly in their process of Bhakti to get Krishna Prema.
"If one offers Me with love and devotional a leaf, a flower, a fruit or water, I will accept it." ~ Bhagavad Gita 9.26
Give Them some nice water every morning, offer Them nice puja. (flower Incense etc) See puja trays in Worship section on RadhikaStore. Offer all your (pure vegetarian) food to Them. (See Deity offering sets) If you like to sew, make Them some nice clothes. Give Them your love and devotion, and just see how your life becomes sublime.
Please note: height measure is done from bottom of base to top of hands.