"Need", in this context, has its usual meaning.  The key here is the use of "seem".  This makes it Deirdre's *opinion* about the woman's state of mind (what she *needs*) and not a statement of fact.  For example:

> Hello, can I help you?  You **seem** to be lost.

I don't know if the person is actually lost, but that seems to be my perception of their state of mind.  I could alternately ask:

> Hello, are you lost?  You **seem to need** a guide.

Again, I don't know if *they* think they need a guide.  That's just my interpretation of the situation.

In the same way Deirde is interpreting the woman's personality, particularly her desires and motivations, while at the same time offering useful advice.  

Because the sentence includes "seem", there's no way this would be interpreted as a *recommendation*.  If Deirde meant to give her advice, she would have written it differently:

> You **need to ask** yourself if you're ready to be a mum.

Side note:  Be aware that [Deirdre Sanders][1] is apparently *not* a licensed therapist or professional counselor.  Moreover [The Sun][2] is well known as a *tabloid* newspaper, meaning that it tends to focus on the sensational and provocative, and many of its stories may not be *entirely* true.  People do seem to find her advice useful and entertaining, as she's been doing this for over 30 years, but her editors *seem to* deliberately select letters by their lurid subject matter, more than their general applicability. 


  [1]: https://www.news.co.uk/who-we-are/toptalent/deidre-sanders/
  [2]: https://en.wikipedia.org/wiki/The_Sun_(United_Kingdom)