Other party has hired a solicitor in the same firm as ours. Conflict of interest?

[BearBibble]

A few years ago I bought a house with a friend (both names on the mortgage, both contributing equally to mortgage, utilities etc), as it was the only way either of us could get on the property ladder. The friendship has now soured to the point that we can't stand eachother, and she has offered to buy me out so we no longer have to live together. We agreed a sale price and each hired independent solicitors to oversee our respective interests in the transfer of my equity to her. However, today I emailed my solicitor to ask for an update on how things were progressing, and he told me that my housemate had fired her solicitor and he had referred her to a colleague in his firm. He says that as he is a consultant for the firm, he and the colleague don't have access to one another's files, so there is no conflict of interest. But it feels really 'off' to me.
Firstly, is it normal that my solicitor and my housemate (i.e. the other party in the case) were even having any direct communication?
Secondly, how can I be sure that being a consultant means my solicitor's files aren't accessible by others in the firm?
Thirdly, our engagement letter advises that our case will ultimately be overseen by the senior partner in the firm - so won't the same person also end up overseeing the other party's case?
I'd welcome any advice a) as to whether this is a normal practice / I'm overreacting by being concerned and b) what questions I should be asking my solicitor when I phone him tomorrow. Thanks in advance!

The solicitors regulation authority, who regulated solicitors, are clear that the same firm shouldn’t act for both parties in a transaction like conveyancing unless there is a very good reason to act which they can justify to the respective clients and them if asked. They also have to have your consent to act for the other party and vice versa. However firms regulated by the Council for licensed Conveyancers can act for both parties. I would complain to the head of the department and say as you haven’t consented they cannot act for you both so either her retainer is cancelled or yours is

Ah, thanks! That was very helpful. So I checked the SRA website and the firm is regulated by them. However, our lawyer as an individual isn't - because it turns out he's not a solicitor; he's a chartered legal executive specialising in property law. Any idea whether this changes things?
The senior partner who we've been advised is "ultimately responsible" for the case is a solicitor regulated by the SRA.

It’s only the regulation of the firm that is relevant to conflicts of interest and their regulatory requirements.

This is a clear breach of rule 6.2 of the Solicitors' Code of Conduct - you can Google it. And not only is there a conflict problem. There is one of confidentiality too. In advising you the firm knows things about you which you don't want the advisors of the other party to know about. Get on the phone to the SRA.