How a mother linguistically interacts with her infant has lasting consequences for the infant's language development (Chase-Lansdale & Brooks-Gunn, 1994; Owen-Jones et al., 2013; Sarsour et al., 2011). There has been insufficient research describing the language environments of children born to young mothers, a term used here to describe both adolescent (18 years old and younger) and emerging adulthood (19-25 years old) mothers. No previous research has looked at maternal age and a specific type of speech, found to be of high importance in the language development process, infant-directed speech (IDS). The goal of this dissertation was to explore the type and quantity of speech infants of young mothers are exposed to, focusing on maternal IDS. I explored these variables by developing a unique labelling system (named ConvoLabel) to aid in the identification of maternal IDS in naturalistic infant language environment recordings completed by young Winnipeg mothers. The sample was comprised of 23 mothers (15 - 25 years of age), and their children (1 - 23 months of age). The Language ENvironment Analysis system, a digital recorder and software system, was used for naturalistic recording and analysis of infants’ everyday experiences (totaling over 600 hours). I found that the young mothers in my sample were using IDS both acoustically, and numerically, in a manner that is like non-young mother populations (of a western context) reported in the literature (e.g., Bergelson et al., 2019; Bunce et al., 2020; McClay et al., 2022). The infants in my sample heard more maternal non-directive IDS than directive IDS, the IDS speech type hypothesized to be more favourable for language learning and infant engagement and responsiveness (Lacroix et al., 2002; McDonald & Pien, 1982; Pratt et al., 1992). The infants were found to hear a significant amount of speech not directed to them which likely plays a role in their language learning process. This research project adds to the limited research exploring how young mothers are talking to their infants, while advancing methodology on the examination of IDS using a unique computer system.