Births Mar Qtr 1870
Sadler Rosa Marylebone 1a 570
1871 census date 2 April
I can see four possible solutions:
Rosa was born late 1869 - fits the reg and died in 1870 [but there is no death reg] and the next one born on 28 Nov 1870 [but there is no birth reg] was a daughter given the same name.
Rosa was born 28 Nov 1869 - fits the reg but does not fit 4 months in 1871 census.
Rosa was born late 1869 or March Qtr 1870 - fits the reg but age 4 months in 1871 and birth date of 28 Nov 1870 are both errors.
Rosa was born 28 Nov 1870 - fits 4 months in 1871 census and the birth reg has an error - the quarter should be Dec or the year should be 1871.
Sadler Rosa Marylebone 1a 570
1871 census date 2 April
Rose Sadler Bap. 4 Apr 1880 - John Robert Sadler & Jane Eliza Sadler Bethnal Green St Thomas Tower Hamlets
Rose (no middle name) and Beatrice Henrietta bap. same day. The image says Rose b. 28 Nov 1870 which matches 4 mo. on the census. Father occ: Turner.
Rosa was born late 1869 - fits the reg and died in 1870 [but there is no death reg] and the next one born on 28 Nov 1870 [but there is no birth reg] was a daughter given the same name.
Rosa was born 28 Nov 1869 - fits the reg but does not fit 4 months in 1871 census.
Rosa was born late 1869 or March Qtr 1870 - fits the reg but age 4 months in 1871 and birth date of 28 Nov 1870 are both errors.
Rosa was born 28 Nov 1870 - fits 4 months in 1871 census and the birth reg has an error - the quarter should be Dec or the year should be 1871.