This is what we refer to as "Spanglish"--part Spanish and part English, and it is absolutely how many Latinx communicate amongst themselves. There is generally a smooth flow between using both languages together with little in the way of "rules" about which language is used for which things. It isn't like "English is used for verbs, Spanish is used for nouns." It is just a smooth ebb and flow between them amongst people who grew up bilingual by necessity and are quite often code-switching in the rest of their lives.
What I find interesting is that Emma and Lyn didn't grow up speaking Spanish. Amongst newer immigrants, it is common to teach children only the new language of wherever they have landed so they assimilate more easily. As you see here, it can cut that new generation off from their own immigrant community.
There's th general phenomenon that what the children of immigrants are not taught for assimilation reasons, the grandchildren do seek out in honor of their heritage, without fears of assimilation factoring in anymore. This exact thing happened in my husband's family. His grandmother was French, but came to the US as a teenager and worked hard to learn English and to speak it with no accent. None of her 7 children speak a word of French. My husband, however, who has never had to worry about assimilating or being the subject of prejudice as from a new immigrant family, is fluent in French because he sought it out in school.
So yes, this is a common language pattern for Latinx people, who usually can also code-switch to some extent into one language or another in other settings.