Yes, and when LM came back home, surely the daughters would express some concern that their mother never emerged from her room. The first thing most spouses (or even ex-spouses) would do would be open the door for a welfare check! We know LM was able to locate the key because he found it later when May's dad showed up. So he must have had a strong reason to refuse to unlock the door.
IMO, the daughters would have certainly begged their father to open the door UNLESS
- their mom shutting them out and ignoring them for long stretches of time was a regular occurrence so it didn't seem unusual to them, or
- they were too afraid to ask their father anything about their mom due to known strife and tension between LM & Maya.
I feel #2 is much more likely than #1. The kids HAD to have known their parents did not get along and I can't see how there wasn't a lot of tension in the house on an everyday basis. Feeling constant tension and perhaps witnessing arguments or worse between their parents would be quite upsetting and frightening for the children, and they may have learned the best way to deal with it was to avoid asking questions or talking about it with their dad. Maybe they quietly & secretly communicated their concerns to trusted members of Maya's side of the family, and that's why May's brother and later father showed up so quickly to check on her.
I suspect something of interest to the investigation was locked in Maya's room until some point on Friday/early Sat morning. Whether any remnants or clues remained by the time investigators came with the search warrant is the big question.