Hi Nikki,
I hesitate to add this in case you already have the information (you have an exact birth date after all), this is the family in 1881
Middlebridge St,Romsey Infra, Hampshire, Source: FHL Film 1341300 RG11/1225/41 p18
Arthur BUTT M 24 M bRomsey, Hampshire,
Head Occ: Master Butcher Employing One Boy
Fanny BUTT M 28 F b Romsey, Hampshire
Wife
Earnest BUTT 4 M b Romsey, Hampshire
Son
Horrace BUTT 2 M b Romsey, Hampshire
Son
Sidney BUTT 8 m M b Romsey, Hampshire
Son
The marriage certificate of the two would help a bit (I presume they married each other??) - you would get their father's names and may be Beatrice's age.
Nell