In the standard General American accent, 'girl' has a single syllable, /gɚl/ or /gərl/.
But a large number of people separate 'rl'. This is similar to how the 'l' in bottle forms a syllable all by itself. This is called a syllabic l'. The sounds (which is not the same as letters) of 'r', 'm' and 'n' also can do that, be a syllable without the usual expected vowel as center of the syllable, though often the schwa 'ə' or 'uh' is considered the syllabic nucleus that comes with a syllabic consonant.
This is not an uncommon variant in all American varieties of English. It is not characteristic of any particular dialect. Some people in all varieties do it. That means that saying it does not pinpoint you to a particular accent, it is an acceptable variation in all accents.
It is not surprising that the consonant cluster 'rl' is sometimes separated. It is often a very difficult pair to pronounce by children and non-native speakers. Notice in the second clip, the announcer, who has a British English accent, gives two syllables for 'squirrel' which is perfectly natural alternative.
This is in contrast to the other direction. Some words, like 'fire' or 'desire', which in the standard pronunciation have two syllables for 'ire' = /aɪ ɚ/ or /aɪ ər/, can reduce to /ar/. It's not like the syllable distinction was emphasized in the standard pronunciation, but especially in the South or in the very similar AAE, they are sometimes non-rhotic (drop word final 'r's) and monophthongization (saying 'Ah' for 'I').