What kind of person is Diana from "The Chaser" by John Collier?

We never find out much about Diana. We can, however, reasonably infer that she's somewhat out of Alan's league (hence his going to see the old man to purchase a love potion). Alan causally mentions in conversation with the old man that Diana's fond of parties. This would appear to suggest that she's a woman who likes to go out and enjoy herself. One gets the impression that Alan would prefer someone who's more of a homebody, a woman who will give him her undivided attention.
At the moment, Diana means everything to Alan, but unfortunately for him she's utterly indifferent to his attentions. But all that will change once she's imbibed a drop of the love potion he's about to buy. Then she'll become completely devoted to him. Alan will become the center of Diana's universe; she'll be insanely jealous of him, not wanting to let him out of her sight; she'll want to know everything that he's been up to each day, every last detail; she'll constantly fuss over him, fulfilling his every need; and if he should ever stray, then she will always forgive him; Diana will never contemplate divorce. To Alan, this all sounds like absolute heaven, so he hands over his dollar with alacrity. But should this picture of domestic bliss turn sour, then he knows just where to go to pick up some "life cleaner" to solve his little problem. Only this time he'll need to save his pennies and pony up the princely sum of $5,000.