Let's look at the available facts;
1). Russ Jordan is facehugged and dragged outside of the derelict.
2). There are multiple facehuggers found in medlab, two are alive after being removed prior to embryo implantation.
Personal interpretation; Those huggers came from the team that were responding to Annie's mayday. Reason: Whether eggmorphing took place or not, we saw that all colonists PDT's (personal data transmitters) were collectively located in the sublevels of the atmosphere processing station.. how likely is it that colonists with small arms and seismic survey charges could venture in and survive retrieving facegugged comrades when fully armed Colonial Marines barely got out in one piece? Not very. Therefore, those dead huggers dropped off the faces of people brought into medlab the same way Kane was in 'Alien'. Expanded media (whilst not canon) shows that this is the case (see 'Aliens: Newt's Tale').
So for point one in the chat debate, no the first alien that burst from Russ did not have to be a queen, there were several xenos loose in the colony prior to establishing a hive.
Where does the queen come from? Two possibilities;
1: it was born a queen (as per Alien 3)
2: it was a regular xeno that went through a metamorphosis.
This is unclear, as there are so many unknown variables. It's sometimes easy to assume we 'know' things about the creatures life cycle based upon years of exposure to expanded media, but everything in the comics etc followed the life cycle as presented in the second movie.. if we just take what we see in the first three movies alone, and filter the rest out, the truth is it's not so black and white or clear. We can debate it till the cows come home, but there is no definitive answer. Did a regular xeno become a queen? Possibly, we saw that xenos in the second movie continue metamorphosis over time (comparing warriors to big chap, losing their head shell etc) it's entirely possible. Was it born a queen? Also possible, we see a queen chestburster in Alien 3. Why is this not definitive proof that the same happened in 'Aliens'? Because there's also the possibility that the queen was a unique evolution to that particular circumstance/environment, given the creatures ability to adapt/survive, the most 'optimum' method of reproduction if you will. Once it was a queen, it may be the case that it produces others like it (hence alien 3). It could be that regular xenos egg morph hosts, and these special ovomorphs, fed on the nutrients of the dissolving host become a sort of 'royal ovomorph'(Alien 3 assembly cut also supports the possibility of superfacehuggers) as per 'special eggs' in real world ant/bee hives. Hell, we're all assuming that the queen was even born from a human host. Could just have easily been born from a colony pet. We simple do not know.
My personal fan theory? Russ and the response team were brought into medlab with parasites attached. They removed two, killing the hosts, and opted not to do the same to the other but monitor their conditions. As per 'Alien' we know that those hosts would have 'recovered' with memory loss (their dead parasites placed in tubes to be studied) and likely been distributed around the colony when they popped. (So 4 xenos in the mix) I like to think this played out like 'Alien' - 4 big chaps, taking hosts, perhaps eggmorphing as a means to increase numbers (the last stand at operations clearly wasn't only 4 creatures, especially when we know the colonists successfully eliminated at least one xeno with seismic survey charges) During metamorphosis, one of the 4 began changing into a queen, with the others becoming 'warriors' (hate this term) building the hive. In this form, the queen can indeed lay 'royal eggs' explaining the queen chestburster in Alien 3.
