Suggestions with cross-border tax accountants in QC or elsewhere in Canada

I am the midst of helping my mother find an accountant to help her with her Canadian-US tax returns. Very briefly: my mother (dual US-Canadian citizen) lived in the US for the past 14 years and my father always handled the tax filings. However, they have since divorced and my mother is now back in Canada and will file on her own for the first time. Given that she is finding the whole process daunting, she would prefer to have an accountant file her taxes (at least for the first year).

I have searched online to find her reputable accountants accustomed with such cross-border filings. Ideally, it would be nice to find one in the province of Quebec, but elsewhere would be fine as well as I assume most documents can be sent electronically.

I have narrowed my search results to the following accountants/accounting firms: Gary P. Gauvin LLC, Phil Hogan, Trowbridge, Serbinski Accounting.

I would appreciate any feedback if anyone has used their services or if anyone can recommend/suggest someone else that they have used.

Thank you in advance for any help you can offer!