I think you have to read the blog post in relation to the one she is responding to. And I don't think you can make any assumptions about the state of her relationship.
Just asked DH and he described it as 'a bit of a hiatus' in our sex life after DD2 was born . I think we had sex a handful of times over almost 3 years. As PPs have suggested had a small gap between DD1 and DD2 (less than 18 months), I was still BFing when I became pregnant and my father was very ill. As soon as I knew I was pregnant we didn't have sex again due to complete and utter exhaustion and emotional stress (because of Dad) until a couple of months after she was born. Then it was painful. So we didn't have much sex for the next couple of years. I got my mojo back after about 2.5 years, we had a couple of months of shagging and then I got pregnant again (so we had 3 under 5 for a while). This time we did have lots of sex when pregnant (more similar to my first pregancy when i was horny as hell) but then not a lot for (again) about 2.5 years at which point something clicked and I wanted to have sex again. Now we have sex as much as we did in the early years of our relationship (we've been together over 20 years) so the lack of sex for years did not have a long term effect.
I think there are some cultures where men aren't allowed to have sex with his wife when she is Bfing and I think there's a lot of sense in that, I think for a lot of women Bfing does dampen sexual desire a lot more than is considered acceptable in this sex-up society. I couldn't bear my nipples to be touched by DH, it just felt so 'wrong' when I was BFing regularly. But I also went off a lot of things that I'd enjoyed before (and enjoy again now) so the map of my desire had changed completely making it difficult to get into the mood. Oh, and I did go off him overnight after the birth. I didn't even really want him in the bed in the first couple of weeks after the birth, I actually was physically repulsed by him at that stage, didn't want to see him naked even walking around the bedroom minding his own business, I was quite shocked by how I felt TBH it was so unexpected. It was something that was completely removed from my conscious mind (he's a fab Dad, does lots of housework and was brilliant during the birth etc).