How long from Hong Kong to take a train at 17:10 Shenzhen North on a Saturday

Hello,
We have to catch a ride to Guangzhou departing at 17:10 from Shenzhen North on a Saturday. We will be departing from Hong Kong Tai Po Market station at 15:00 Do you think we have time? Google Maps tells us we should arrive at Shnzhen North at 16:07 But we don't know how long the Hong Kong - Shenzhen boarder check actually takes. Also, we have to collect our tickets first as we cannot do it from Hong Kong (except if you would know how)

Thank you so much for helping out