Cranfield is in Ampthill registration district so I think you need to regard any Bedford registration district births with a lot of suspicion. These were still early days with civil registration so quite a few births were not registered.
In 1861
- there's an Eliza Goff age 11 born Bromham Beds living in Marylebone. Bromham is in Bedford reg district so I think she is more likely to be the 1850 birth
- there's also a 7 year old Elizabeth M Goff born Bedford, living in Bedford in 1861. I wonder if she's the June 1854 birth - her father married as John Estick Goff so I wonder if the middle name of Elizabeth Shirck Goff is a corruption.
- another 11 year old Elizabeth Gough born and living in Bromham probably takes care of the June 1850 Elizabeth Gough in Bedford.
- there's a Jane Gough 23 and Eliza Gough 16 both unmarried, both born Cranfield living as lodgers in Luton. Jane appears to have been christened in Cranfield on 6 Aug 1837 as Jane Goff, daughter of Sarah Goff, so may have been illegiitimate (per IGI - extracted entry). There's another baptism in Cranfield of Eliza Gough on 11 May 1845 daughter of Elizabeth Gough so she may have been illegitimate too - this one seems favourite to have married in 1889 aged 41 (ish!) and to be the niece of Susannah in 1871 and 1881. To summarise in response to your original question, I think the 30 year in 1881 is the same one who married in 1889 aged 41, although she was actually born in 1845!.
Regards
David
