A belated Happy Birthday to you, Caroline! Marilyn in Canada

Hi, I just checked the IGI and found a record for the marriage of Ann CUTLER to Peter GAWLER in 1777 in Christchurch, Hampshire. There is a new format now and the birth for Ann CUTLER was given as "About 1750 Christchurch, Hampshire, England". It went on to say that this had been submitted by someone in the LDS Church. I have not seen this IGI entry previously and I have looked lots of time. I'm just wondering why an exact date for Anne's birth is not given. This is the person I am interested in. Can anyone advise? Thanks Susan in Guelph P. S. Happy belated birthday to Caroline!