How to file online self assessment with NI number under maiden name

Hello. This will be our first year filing self assessment after moving to UK from USA. My wife applied for and received a UTR. In order to set up an online Gateway account it appeared that a NI number was needed, so she then applied for a new NI number even though she is retired and will not work. The response we received showed that she already had a NI number under her maiden name when she had lived in the UK 40+ years ago. The number is in the process of being updated to her current married name. When we try to set up an online account for her and enter the NI number we get an alert saying it does not match their records. All income is US pension and above the personal tax allowance. My question is, Is there a way to file SA 100 and SA106 online with out an account? Is it possible to open an account with the UTR but without the NI numberOr will we have to file paper forms before October 31st? Thank you.

Hi,
Your wife should contact us by webchat or phone via  Self Assessment: general enquiriest -
we can then confirm if any amendments are needed to the details we have for her on record, which we then use to allow access to her online account.
If she cannot file online, she will need to send a paper tax return.
Thank you.