Middle name missing on E-Ticket - China Southern Airline (CSA)

Hello,

We will be travelling to Guangzhou for a long stopover for four days to enjoy the sights before heading to our final destination, Philippines.

To my horror, I noticed that my wife's middle name is missing from the E-Ticket, do you think this will be an issue because from what I have been told, I will have to pay a very hefty price to amend it?

I contacted the agency TravelUp to ask this who in turn apparently contacted CSA and said they're not really bothered about the middle name, only the first and last names must be amended/included.

I finally managed to contact CSA myself and asked the question too. I'm not sure if this was a direct representative of CSA because she asked which airline was it (even though I called the number on CSA's website) but she gave a vague answer. I asked if I should rebook it and she replied "It's up to you"! Not a helpful answer and now I'm very worried.

Would you know if it will be okay if I leave it as it is? We have British passports and are flying from Heathrow Airport, UK.

Thanks very much and hope you can help.

Kind regards,

David