I think we need to go back to basics here and establish exactly what size you require as you are clearly confused, having stated that you want both E14 and E27 in different posts!
Do you know where you sister bought the lamp can you provide a link or give an absolute and definite answer as to which size fitting you require?
I'm being nosy but why do you need two side lamps with 100W bulbs, do you do some sort of fine needle work that needs such a very bright light. If that is the case you'd do well to investigate craft lights.
Jennyjoan, please do not do this. The maximum sized bulb to go into a table lamp is 60 watts, anything larger & you risk a serious fire disaster. Why don't you do as suggested & fit energy saving bulbs which you can get these days in a much lower wattage but will give you the equivalent light output of the old 100 watt bulbs.