can't gain weight 😩

OMG I'm 25 weeks and only gained 13lbs I was 123 before pregnancy & can't even tell.. I was always skinny/slim and had fast Metabolism and was hoping to gain my dream weight I always wanted. When I gain weight on my face it makes me look better because I have a long face and can't do certain hairstyle that I wanna try because it doesn't fit me lol but I'm hoping to gain weight. Any tips on what healthy foods my help me ?