Worried mom

My daughter is 3 yrs old and 6 mos.now but still she cant speak a sentnce.2-3 words,clearly evrytime she sing a nursery rhymes.i just know it because of the melody and tune of the song. She also know how to mimic a dance steps or any actions that mybe catch her attention when saw it twice. Is this normal? Any advice in her condition to enhance her speaking skills or do ihave her checked up? 🙏🙏🥺🥺