When they were reunited at the weekend at Asda in Lower Earley, Krista was at last able to laugh with proud mum Jay Platt about the most unusual customer inquiry she has ever had to deal with.
She said: "Jay comes into the shop quite regularly, so I recognised her when she came over to the desk in tears saying her waters had gone.
"I thought 'oh no' and called for first aid assistance because I'm not trained, but no-one came, so I abandoned a queue of customers and took her to the security office with the security guard."
Jay, 25, was with partner Oliver and their 20-month old twins Faith and Kyra, and she said: "We were in the fruit section putting bananas in the trolley because my partner loves bananas, when I looked down and saw that water had gushed everywhere.
"I couldn't believe it because my waters didn't break at all with the twins."
Krista dialled 999 and an ambulance controller stayed on the phone to give her guidance. She said: "They asked me if I could see the baby's head and I said 'no', but the contractions had started coming quite quickly at that point."
Jay was taken to the Royal Berkshire Hospital by ambulance, but nothing happened until five days later on April 23 when son Blake George was born - named after the Asda clothing range and because his birthday is St George's Day.
Jay, who lives off Rushey Way, said: "My contractions actually stopped when I got to the hospital, and I ended up having to be induced.
"The baby wasn't actually due until the end of May, so it was a huge shock to go into labour - it was all very unexpected.
"Oliver rushed the girls to stay with family and Krista was absolutely amazing, she stayed with me the whole time and reassured me so much."
Krista, who has two children herself and has worked at the store for 16 years, added: "I have never had to deal with anything like that before, and I went straight on a tea break afterwards!
"Everyone at the store was talking about it, but I was happy to help and I've been round to visit the baby since."