Dr. Turner was born in 1909 (according to Stephen Mcgann's book 'Dr. Turner's Casebook') and Shelagh was born in either 1925 or 1926 (in Series 6, Episode 3 when Shelagh is in hospital the consultant says she is a 36 year old elderly primigravida). So in Season 12 they are 59 and ~42.
In real life Stephen McGann was born in 1963 and Laura Main in 1981, so their characters' ages reflect their real ages.
I think Shelagh probably was pregnant. In addition to the dead rabbit symbolism, she was sniffing the bowl of eggs (remember her sensitive stomach when she was pregnant with Teddy?).
