Research on second language learning by children with DLD has mainly focused on naturalistic L2 acquisition with plenty of exposure. Very little is known about how children with DLD learn foreign languages in classroom settings with limited input. This study addresses this gap and targets English as a foreign language (EFL) learning by Russian-speaking children with DLD. We ask whether learners with DLD benefit from a later onset of EFL instruction because older children are more cognitively mature and have more developed L1 skills. The second aim of this study is to determine whether EFL learners with DLD benefit from positive L1 transfer in vocabulary learning. We administered a receptive vocabulary test to younger (Grade 6, n = 18) and older (Grade 10, n = 15) children with DLD matched on the amount of prior EFL instruction. The younger group started EFL instruction in Grade 2 and the older group in Grade 6. The performance of the two groups was compared after four and a half years of English lessons. Half of the words in the test were English-Russian cognates and half were noncognates. Contra to our hypothesis, the results showed no difference between younger and older children. Both groups equally benefitted from cognate vocabulary suggesting that positive cross-language transfer is available to children with DLD, irrespective of their age and onset of EFL instruction.