Translation:My husband's father and mother are my in-laws.
Good question! Because 'e'nal is understood to mean in-law, we tend to think of it as working the way English in-law does. But you're right: the word has a less broad definition for Klingon that doesn't seem to support this sentence. You married into your husband's family, and your husband married into your family, but from your point of view your husband's mother and father didn't marry into your family.
There was a further use of 'e'nal from Okrand, however, in which he said that one's wife's brother's wife would be called 'e'nal. (The original question was whether Klingon had terms for brother-in-law and sister-in-law. It doesn't.)
So there is some support for the idea that Klingon 'e'nal has the same breadth as English in-law. More clarification from Okrand would be helpful.
This sentence's word order was very confusing to me. Could someone break it down and explain it please?
Probably the most important part of understanding a Klingon sentence is finding the verb. As you get used to Klingon sentence structure, you'll get used to listening for the different parts as them come. But as a beginner dealing with written sentence, you can start by finding the verb.
In this case the verb is chaH - a pronoun acting as the verb "to be". Everything before the verb is what "they are". Everything after the verb is who "they" are.
The je at the end tells us there are multiple nouns joined together and it is preceded by three nouns. Under other circumestances there would be ambiguity whether you might be talking about "my husband, the father, and the mother" or "my husband and the father's mother" or "my husband's father and the mother" or "my husband's father and mother." However in this case we have a small piece of clarifying information. The actual noun being referred to must be marked with -'e' because it is required when using a pronoun as "to be". Thus we know that vav'e' and SoS'e' are the nouns represented by chaH and since loDnalwI' is not marked with -'e' it is a descriptor, not one of the nouns in question. Thus the last three nouns plus the conjunction must form the noun phrase "my husband's father and mother".
"my in-laws"<-they are, (speaking about:)"my husband's father and mother"
Once you have broken down the sentence, I recommend you read it out loud a few times concentrating on reading it in order, but thinking about what each part means as you say it. This way, your brain can begin to get used saying and hearing the parts in proper order.