Questions & Answers about Ihr Enkel ist noch ein Baby.
Ihr can mean "her", "their", or "your". How do we know which one it is here?
You usually need context to know for sure! Because Ihr is the first word in the sentence, it has to be capitalized. Without the English translation, it could just as easily mean "Their grandson" or the formal "Your grandson".
Could noch ein mean "another" in this sentence?
That is a great guess, but no! While noch ein often means "another" (like in Ich möchte noch ein Bier for "I want another beer"), here the verb ist (is) makes the context clear. He is "still a" baby, rather than someone being "another" baby.
Why does Baby use ein instead of einen?
The word Baby is neuter (das Baby). Also, the verb sein (to be) is a linking verb, meaning the noun that follows it stays in the nominative (subject) case rather than changing to the accusative (object) case.
Since Baby is an English word, how do we make it plural in German?
English loanwords usually take an -s for the plural in German, and they do not change the "y" to "ie" like in English. So if her grandson had a twin, they would be zwei Babys.