Walking not attained at 16 months. Do?

My baby girl now 1.4 months old with current weight 7.8 kg with birth weight 1.75 kg , 36 weeks preterm cs twin delivery with no ICU admission or any other relevant post natal history. Her most of the milestones like crawling , sit without support is a slightly delayed. She used to do creeping more than crawling . Crawling attained at 10 months, sit without support at 9 months. She used to stand without support  and  take one or 2 steps 1 month back.By march 1 St week she had a high grade viral fever which lasted for 5 days . Now she is walking with support . She just need  one finger to hold for walking. She is walking properly with support. When we remove our hands, she is crying and immediately she is sitting down. After that fever, she is crying  when she stands without support. it's like she is scared to walk without support.She is blabbering a lot and using single syllable like  mma for Amma , ccha for achan. Not saying bisyllable words . Please advice. What should we do?