The examples in the documentation give a very good indication of how to align an Entry widget with its Label widget. In the examples, the vertical position (Entry.y) of the "Entry" is placed minus 4 pixels from the vertical position (Label.y) of the "Label".
local label = ui.Label(win, "Name : ", 80, 75)
local entry = ui.Entry(win, "", label.x + label.width + 8, label.y - 4, 100)
-- from the Entry:onSelect() documentation
According to my research, minus 3 pixels would be a better choice, because then the text in the entry is on the same line as the label text.