The projection of others and their bias relating to their own cases has no bearing on how Family Law works, which is on a case by case basis.
There are posters on this thread who know exactly how family law works for reasons that have nothing to do with their own case. You do not appear to be one of them. That is quite clear from your suggestion that the OP does not need any evidence for safeguarding concerns. The courts would not agree with you.
I have never been involved in contact proceedings relating to my own children. My comments are not, therefore, based on bias relating to my own case. They are based on knowledge of family law and how it is administered in practice.
Each case is looked at individually but there are some basic principles that are always followed.
The courts believe it is best for children to have a relationship with both parents and will support that unless there is clear evidence that it is not in the child's interests.
The courts believe that neither parent has any right to say what the other parent does or who they see with their child. They will only implement restrictions if there is clear evidence of safeguarding concerns.
The courts are familiar with parents who invent safeguarding concerns as a way of trying to stop or limit contact. Allegations are ignored unless the parent can provide evidence.
You say the OP is "rightfully" concerned over her child's safety. Nothing she has posted indicates that she has any evidence for her concerns. She has exchanged some texts with the other woman which, unsurprisingly, have not been pleasant. That is not something the courts would accept as indicating safeguarding concerns. If there was evidence that the other woman had abused children in the past or threatened the OP's child that would be a valid concern. Exchanging some unpleasant texts is not.
If the OP follows your "advice" and this ends up in court her ex will be able to use her actions as evidence that she is unreasonable. The courts do not like parents who restrict contact citing safeguarding concerns for which they have no evidence.
In the short term the courts would probably cut the OP some slack on the basis that emotions are raw. But they will absolutely not support the OP in putting restrictions on her ex's contact with their child in place based on nothing more than some unpleasant text messages.