I think her lips are better than Aish's...Aish's look very fake while hers look more natural...nothing is supposed to look perfect...one side is always smaller or something...I bet u Aish's lips are fake...and anyway...Aishwarya's full name is Aishwarya Rai...and the girl in Lucky...her name is Sneha Ullal...so there is no possibility that they're sisters...unless maybe their mom re-married...but there is no news of that...so she's not her sister...but it's true...they resemble each other A LOT!...here are some pictures...
Look at their resemblance from the side...
Look at how similar their eyes are...their lips are similar too...but they're a little bit different...Aish's upper lip pouts a little more...but their eyes are so much alike...