Now this may not be the case at all with this car & I'm sure it was serviced on the button but in my experience basic, lower end, low mileage cars owned by elderly people are rarely serviced on schedule. If, say for e.g., the recommendation is 'every 6,000 miles or 12 months' & the car is driven 1,500 - 2,000 miles pa then it gets serviced every 3 or 4 years. The 'every 12 months' bit gets forgotten & the SH gets lost with statistically improbable frequency.