I've been talking with my girlfriend about exercising for weight loss. She's fairly okay with the idea, but I think she's holding back because she was born with a slightly abnormally shaped heart. The doctor gave her the go on exercise provided her heart doesn't pass 160 bpm.
She's never lifted, is 5'5" and about 160 lbs (I haven't asked her her exact weight because she's still a little shy on the topic, but I'm guessing it's about that). She's also genetically predisposed to a lot of weight gain, which is pretty important to avoid because her heart isn't great. Let's say her goal is to lose 8-10 lbs as a healthy start (we haven't talked it out, but I think she'd agree to that as a starting point). So, dieting, light cardio, and weight training that doesn't stress her heart too much are all on the table. I want to convince her that she can reach this goal mainly through dieting and weight training. But I also don't want to feed her false expectations about what she can achieve in a reasonable amount of time. Any advice?
By the way, part of my obliviousness to this is that I'm naturally skinny. My only problem has ever been about packing on weight, so I'm pretty hesitant to tell her anything not having been where she is at.
[edit: fixed some typos]