At first sight of your question, I was tempted to answer quickly 'Yes', but, reading it in detail, I thought this is a very difficult question to solve. In order to solve this linguistically and to understand the general uses of むすばれる and むすばれた, first of all, let's have a look at some examples.
- 心とからだの準備をしっかりして、より素敵な夜を過ごすために、いつどんな場面で結ばれるのかを、あらかじめ知っておく必要がある。(in this sentence, 結ばれる signifying intimate relation)
Interesting for me indeed, むすばれる（むすばれた）in most of these examples represent the mental or spiritual bondage or linkage between the two. In order to find むすばれる（むすばれた）with the meaning of intimate relation, I did some research on the web by using ホテルでむすばれた. I found, of course, some examples of this meaning, and among them a very interesting one for me and probably for you.
The writer of this sentence had to put 男女として before むすばれる, for the purpose of clear statement of their intimate relations. Now we can safely say that むすばれる（むすばれた）put much more emphasis on human, mental, or spiritual bondage between the two and that they have to come closer and closer and reach a certain top of, say, marriage or something like that.
Now, let's return your specific case in the show. I watched only some parts and its summary. It seems to me that むすばれる is the most important key phrase in this drama because of the symbolic name of the boy friend or partner is 結人(read yuuto, literally musubareru+hito). Grown up in a new house which cannot be called her home because of the lack of strong human relationships among the family members, the main character was told by her mother「結人と結ばれたのね」. The human relationship reached at a certain top in mentality or spiritual state during her 35-year-life without mutual warm human relationships. In this show, it does not matter whether the main characters had sex or not, and the scenario writer must have thought that this kind of sexual things should not need to be mentioned or hinted, and he probably intentionally avoided this in order to focus on her spiritual purity. This was surely one of her tops in her life, even if she did not get married formally. But I do not know her later life at all.