Making a pre-auction offer to my landlord

Myself and my partner are FTB, currently renting a lovely flat in the West of England (for 1yr). Recently we found out our landlord is selling our flat at auction, plus 2 others, due to some traumatic life events. Auction is scheduled for late May (~7 weeks time) with guide price listed, and its significantly below market value.

We spoke to the landlord directly and offered to buy the flat for 10% above guide price (we have an MIP and 15% deposit available in a LISA). She said a year ago she would have scoffed at that price, but given the circumstances, she'd be willing to sell to us if we can ensure a quick, easy sale. BUT she said we still need to go through the auctioneers.

This complicates things. The "pre-auction offer" seems risky as mortgage buyers - we'd need to pay 10% deposit before mortgage is agreed, and though affordability is not a concern, I'm very aware of horror stories where lenders back out after deeming auction properties high risk. Quotes for solicitors with auction experience are also pretty hefty. We have a lovely broker, but not sure if we'd need to find a specialist for this situation.

Given that we already have a relationship with the landlord, can we simply offer a direct sale, solicitor to solicitor? Is she contractually obligated to involve the auction agents? We'd be willing to cover the sunk auction fees / withdrawal penalties but unsure this is a 'viable' route to sale. Some advice would be really appreciated.

If it's a case of needing to go via Pre-auction route, how can we best protect ourselves?

Flat details:

Five storey Grade II listed building, 180 years remaining on lease, no major works planned. Manageable service fees.

Auction details:

10% deposit on exchange (would ideally use LISA funds). 8 week completion, £1700 buyer’s charge.