Board Thread:General Discussion/@comment-3994738-20130204201451/@comment-199.17.222.10-20130302043223

Anna started to appeared in 1985 (28 years ago) and had Robin in 1977 (36 yrs + approx 20 years due to her working for the fictional WSB agency in 70s = 56ish)

Heather appeared in 1976 and had Steve in 1977 (revised 1973) (40 yrs + 23ish = early 60s)

They might be close in age, but I might speculate that Heather might be a tad older than Anna. This is just want I found, no conclusive answers but something to go on