Hi,
I went to the Toronto Reference Library and had a look in the London directories and I think I found Beatrice and Frank. Sometimes the work address is given and sometimes the home address - so I think I have interpreted this correctly -
1925 - Frank Bolton is a stoker at Ontario Hosp
1926 - Beatrice I is a clerk at FW Woolworth, 8 Perry Street (I wonder if this is her - there are no other Beatrice Boltons in the directory, but if she was a homemaker, she wouldn't be listed separately.) Frank Bolton is a labourer with an address of 417 Bathurst. (This may be a work address)
1927 - Beatrice Bolton is a cook at Victoria Hospital. Frank is a cooper. For both, a home address is given - 251 1/2 Wellington street. This would have to be your Beatrice and Frank.
1928 and 1929, neither of them is in the directory.
1930 - Frank works at Lon and Pet Barrel company. This would make sense if he was a cooper. I expect the short forms stand for London and Peterborough - or something like that.

1931 - directory is too delicate to handle, so I didn't look at it.
1932 - Frank is still at the Lon and Pet Barrel Company. There is a Beatrice Bolton who is a saleslady at the Red and White store, 8 Perry Street. (this would be the Woolworth store mentioned above). I don't know if she is your Beatrice or not.
1932 - Frank dies
1933 - Beatrice Bolton (wid Frank) works at McCormicks, address 365 Ontario Street (I think this is her home address). There is another Beatrice Bolton who is a clerk at DH Wright at 7 Perry street. This is the only year when there are 2 Beatrice Boltons listed in the directory. The Perry street work address makes me wonder if the Woolworth/Red and White Store Beatrice is this second one??
This is really odd
1934-1937 there is only one Beatrice Bolton in the directory and she works at McCormicks as above. She is listed as (wid George) in all of these. There is no George Bolton in any of the earlier censuses who could have been her husband. I think I saw one or two, but they had their wives' names in brackets next to their own names - no Beatrice. Did Frank have a middle name or did he use the name George or is this just an error that never got corrected? Odd

1938 and on - no Beatrice. Perhaps she married again or moved elsewhere. If you are looking for a second marriage you might want to look at 1938/1939/1940.
I know this is a bit confusing, but at least it gives you some information that might be helpful if you were to contact the London Library.
RK