You will make most of your judgements from text before you ever meet. Some things show up early and reliably.
The message that was sent to everyone
Generic, complimentary, and about them. It costs nothing to send fifty of these. It is the reason opening a chat here costs tokens: friction is what makes a message mean something.
Deflection on specifics
Ask what legal position they want and see whether you get an answer. Vagueness at this stage is not shyness — it is either an absence of thought or a difference of view being postponed.
Any mention of natural insemination
End it. No context makes this appropriate. It is the clearest signal available that someone is here for a reason other than helping you have a child.
Money that appears early
Reasonable expenses exist and are discussed openly and late. A payment raised in the first conversation, or a fee framed as covering something unspecified, is a different thing entirely.
Flattery instead of questions
Someone about to help create a child should be curious about the child’s future. If the enthusiasm is entirely about you and not at all about that, notice it.
Pressure of any kind
To meet, to decide, to skip a step, to keep it between you. Every one of those is worth a pause, and the reaction to your pause is more informative than anything said before it.