Some people follow the custom of asking either relatives or members of the community to bless the baby as they see fit. Siblings may cite the blessing Rivkah's family blessed Rivkah and grandparents may choose the blessing that Yaakov gave his son and grandsons.
Achoteinu at heyi li'alfei rivavah
Our sister, be you the mother of thousands, of ten thousands. (Genesis 24:60)
Ha'Elohim asher hit'halchu avotai lifanov Avraham vi-Yitzchak, Ha'Elohim ha-ro'eh oti ma'odai ad ha-yom ha-zeh: ha-malach ha-go'el oti mi-kol ra yivarech et ha-na'arim vi-yikra bahem sh'mi vi-shem avotai Avraham
vi-Yitzchak vi-yidgu li-rov bi-kerev ha'aretz.
God before whom my fathers Abraham and Isaac did walk, the God who has been my shepherd all my life long until this day, the angel who redeemed me from evil, bless the lads and let my name be named on them, and the name of my fathers Abraham and Isaac and let them grow into a multitude in the midst of the earth. (Genesis 48: 14-16)