My child was born in thailand and I did the uk passport for her . She is coming to England soon and I will do her thai passport in England . Will my wife have any problems leaving thailand has the new passport does not show she has entered thailand

No, she will just need to show the birth certificate that explains why there is no entry in her passport and immigration has no details of her.

To be sure, send her a note giving her permission to take the child abroad. Immigration now sometimes checks.

Best is to also get a Thai passport before she leaves.You only need to get the form giving permission stamped by the embassy and she can than use it in Thailand at the passport office and recieve the passport a few days later.

No, she will just need to show the birth certificate that explains why there is no entry in her passport and immigration has no details of her.

To be sure, send her a note giving her permission to take the child abroad. Immigration now sometimes checks.

Best is to also get a Thai passport before she leaves.You only need to get the form giving permission stamped by the embassy and she can than use it in Thailand at the passport office and recieve the passport a few days later.

My wife said she can't get a passport for our child unless I go with her and our baby . She has already asked at the local office . It also says this on the embassy website

That is a small misunderstanding. Both of you must sign the passport application, but only one of you must appear in person. The other parent can sign the passport application at the amphur, in your case the embassy. They will stamp it as true and then you send it to your wife and she signs the form and goes to the passport office.

In addition to what Mario says, getting a passport in Thailand takes 3 days. Doing it at the embassy will take up to 2 months. You don't want to have your child having to return to Thailand on the UK passport and be subject to Thai immigration rules as as they entered as a foreigner.