Dr worried about weight ?

I posted something a while back about being underweight in my pregnancy an not having an appetite since I was about 28weeks. So I went to the doctors this morning and I gained 14 lbs in one month I was 120 now currently 134 and my doctor said she’s worried about How much I have gained in such little time. Now what do I do .. I hardly eat as it is and when I do it’s fruits and eggs and yes I do eat French toast or potatoes in the morning for breakfast but that usually is my biggest meal an the rest are very small portions of food. Although she did say my baby was healthy an she is doing fine she is still concerned for me , Has anyone ever experienced this ? An what should I do ... I love fruits an granola I snack on those the most but she said no more fruits and salts

Ps: I’m 4’11 so she said I started at 105 an now 134 I’m petite an it’s not healthy