Daughters are a great blessing because Allah(SWT) has promised a place in paradise (Jannah) on bringing them up. The one who has 3 daughters or sisters, or 2 daughters or sisters and he brings them up properly and fears Allah(SWT) regarding their rights, then Paradise is made mandatory for him. In some Ahadith, when the Prophet(SAW) mentioned the blessings of bringing up 3 daughters or sisters, somebody asked “What if someone has only 1 daughter?” The Prophet(SAW) mentioned the same prize for him as well,i-e a place in the paradise. Paradise would never be made mandatory for such people had daughters not been blessings of Allah(SWT).