David Laufer's suggestion of an infant death has made me think again.
It would have to be the first-born Hani (1866) who died, and before the
birth of the second-born (1869) who might well be given the same name.

Birth records specify dates of birth and parentage.
Marriage records specify dates of birth and parentage for both partners.
Death records often give rough dates of birth, and usually name of
partner. Rarely parentage.

We can assume that a 3-year discrepancy in d.o.b can be explained away,
but a discrepancy in parentage cannot. Nor can a (serious) discrepancy
in husband's name.

Hani (b 1866) could well have pretended on marriage that she was born
1869 even if in fact it was 1866.
There is only a problem, if the husband in the 1898 marriage didn't have
the same name as the one in the 1905 death record. ( with Jewish names,
that needs careful inspection.)

In that case, Hani must have married twice, and there will be a second
marriage record to be found. I wouldn't search too hard for an 1869
birth record!

One thing we're all agreed on is that two sisters living with the same
parents and having the same name is unthinkable.

Eva Lawrence
St Albans, UK.