Gaining weight ??

Hey ladies , I stumbled across the "TTC and your weight" thread . I'm just courious on if anyone can offer any advice that helped you , or someone you know gain weight ! Im five foot , and weigh 102 . I've always been petite .. But I'm smaller now then I was pre-pregnancy. I am breast feeding , were going on month 13 . I'm trying to wean but it's a process that's a lot easier said then done . I just feel so thin , I've always been healthy . I eat more then I should , but I have a very active metabolism. So that and breast feeding as we'll has put a strain on my weight . So any tips on gaining weight , if anything will work since I'm BF . ?