My baby 6 months 15 days old still not sitting her own should I worry and please let me know when babies sit there own ? She is low birth weight baby and her weight is 2.250 grams

A. babies strt to seat around 6 to 8 mnths . keep encouraging the baby as use Babyhug booster chair or Babyhug high chair.. massage well.as massage strengthen bones and helps reaching milestone in time...