Sorry, you're both speculating.
1.We cannot possibly know how AA or FS would have acted had either of them had an illegitimate child. Home-made anecdotes regarding our own relatives shed zero light on this situation.
2.We can be virtually certain that the woman known as AA had a child: Her cervix was examined by a doctor as part of a physical, and it was determined that she had given birth at least once -- and this was something she confirmed herself.
3.AA did not consider her child illegitimate, for she believed that she went through a ceremony of marriage with Alexander Tschaikowsky. There is some reason to suspect that the ceremony -- as described by her -- was an ordinary mass rather than a marriage, but this is only speculation also.
4.The Romanian orphanage is not a cover story. There is quite a bit of evidence to support AA's assertion that she gave her child up for adoption; someone did a bit of research into the matter during the trial -- I believe it was Dominique Aucleres, though I could be wrong here.
5.There is absolutely no evidence -- NO evidence AT ALL -- to suggest that FS was ever pregnant. Her family denied it; her family saw her shortly before her disappearance, and had seen her on a fairly regular basis since she moved from Borowy Las to Berlin -- and remember that her own sister Gertrude lived with her for some of that time in Berlin. Remember also that she was in and out of various hospitals and asylums, and under fairly regular, if not constant, doctors care. From the time she left her parents' home to the time of her disappearance, she was never "unattended" by either family or medical personnel for more than a few weeks at a time. All of this is easily established by the evidence accepted at the German trial.
6. However, for the sake of argument, lets give FS a mythical child: In this case we would have to say that there is absolutely no evidence to suggest that FS's hypothetical baby died in miscarriage, early childhood disease, trauma, whatever. The only contact we can be sure she had with any man was with her fiance -- and we don't know that there was sexual contact at all. She met him in 1915; he died in 1916 -- she is well accounted for during this time.
Sorry, but this speculation over FS's hypothetical child, and the disregarding of known facts about AA's child is certainly bad history -- you do it because it allows you to conflate the two women into one -- but the matter of the child is one piece of evidence that keeps them apart as separate individuals in my opinion.
And rsskiya -- you keep telling people how to behave around here, yet you keep loading your posts with snide comments towards those you don't like. Just stop it. You're not fooling anyone.