2 1/2 yr old still not saying much..

So my little boy is 2 1/2 and we have an almost 3 month old baby girl. Our little boy only says hi, mamma, dadda, nana and papa and sissy...we have him in speech therapy he’s been going to that for a while and hasn’t made much progress... we were gonna get the tongue tie reversal procedure done but the doctor that was going to do it said he didn’t need it... have any of you been in this situation... I still think he’ll start talking when he’s ready but everyone else (family wise) thinks he needs more help... suggestions??